25 files changed, 394 insertions, 95 deletions
diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index b95afd8..463d3d7 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -80,6 +80,7 @@ set(DOC_FILES
         starting.doc
         trouble.doc
         xmlcmds.doc
+        emojisup.doc
         language.tpl
         maintainers.txt
         translator.py
diff --git a/doc/Doxyfile b/doc/Doxyfile
index ceb6385..bdd1098 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -38,7 +38,7 @@ INPUT             = index.doc install.doc starting.doc docblocks.doc markdown.do
                     autolink.doc output.doc searching.doc extsearch.doc customize.doc custcmd.doc \
                     external.doc faq.doc trouble.doc features.doc \
 		    doxygen_usage.doc doxywizard_usage.doc \
-		    config.doc commands.doc htmlcmds.doc xmlcmds.doc language.doc \
+		    config.doc commands.doc htmlcmds.doc xmlcmds.doc emojisup.doc language.doc \
                     perlmod.doc perlmod_tree.doc arch.doc changelog.doc
 FILE_PATTERNS     = *.cpp *.h *.doc
 EXAMPLE_PATH      = ../examples
diff --git a/doc/arch.doc b/doc/arch.doc
index ed9d579..bd51a1b 100644
--- a/doc/arch.doc
+++ b/doc/arch.doc
@@ -248,7 +248,21 @@ Note that by running doxygen with `-d lex` you get information about which
 <h3>Testing</h3>
 
 Doxygen has a small set of tests available to test, some, code integrity.
-The tests can be run by means of the command `make tests`. When only one or a few tests are required one can set the variable \c TEST_FLAGS when running the test e.g. `make TEST_FLAGS="--id 5" tests` or for multiple tests `make TEST_FLAGS="--id 5 --id 7" tests`.
+The tests can be run by means of the command `make tests`. When only one or a
+few tests are required one can set the variable \c TEST_FLAGS when running the
+test e.g. `make TEST_FLAGS="--id 5" tests` or for multiple tests
+`make TEST_FLAGS="--id 5 --id 7" tests`. For a full set of possibilities give the
+command `make TEST_FLAGS="--help" tests`. It is also possible to specify the
+`TEST_FLAGS` as an environment variable (works also for testing through Visual
+Studio projects), e.g. `setenv TEST_FLAGS "--id 5 --id 7"` and `make tests`.
+
+<h3>Doxyfile differences</h3>
+
+In case one has to communicate through e.g. a forum the configuration settings that 
+are different from the standard doxygen configuration file settings one can run the
+doxygen command: with the `-x` option and the name of the configuration file (default
+is `Doxyfile`). The output will be a list of the not default settings (in `Doxyfile`
+format).
 
 \htmlonly
 Return to the <a href="index.html">index</a>.
diff --git a/doc/autolink.doc b/doc/autolink.doc
index ff468e4..bf9fe57 100644
--- a/doc/autolink.doc
+++ b/doc/autolink.doc
@@ -80,7 +80,7 @@
     are required to identify the target, i.e. 'func(int) const' and 'func(int)'
     target different member functions.
   \par Note 3: 
-    For JavaDoc compatibility a \# may be used instead of a :: in 
+    For Javadoc compatibility a \# may be used instead of a :: in 
     the patterns above.
   \par Note 4:
     In the documentation of a class containing a member foo, 
diff --git a/doc/changelog.doc b/doc/changelog.doc
index 0b245b6..ca00728 100644
--- a/doc/changelog.doc
+++ b/doc/changelog.doc
@@ -718,7 +718,7 @@
 <li>Bug <a href="https://github.com/doxygen/doxygen/issues/5569">5569</a> - Fix a potential null pointer dereference in src/searchindex.cpp [<a href="http://github.com/doxygen/doxygen/commit/e21aaadb920775f431a27957542da80e39d0c947">view</a>]</li>
 <li>Bug <a href="https://github.com/doxygen/doxygen/issues/5570">5570</a> - Fix wrong pointer initialization in src/definition.cpp [<a href="http://github.com/doxygen/doxygen/commit/cb5d8e6198fe0d0852fb06d6fa18b8ae2682e2c0">view</a>]</li>
 <li>Bug <a href="https://github.com/doxygen/doxygen/issues/5571">5571</a> - Fix potential modulo by zero in src/template.cpp [<a href="http://github.com/doxygen/doxygen/commit/c4007c3abea9c8494bf32181a1352b5366bede69">view</a>]</li>
-<li>Bug <a href="https://github.com/doxygen/doxygen/issues/5572">5572</a> - Reached end of file while still insided a (nested) comment in Markdown [<a href="http://github.com/doxygen/doxygen/commit/c7f7c954ec1356e7f361da0d655c72ca0012a0cf">view</a>]</li>
+<li>Bug <a href="https://github.com/doxygen/doxygen/issues/5572">5572</a> - Reached end of file while still inside a (nested) comment in Markdown [<a href="http://github.com/doxygen/doxygen/commit/c7f7c954ec1356e7f361da0d655c72ca0012a0cf">view</a>]</li>
 <li>Bug <a href="https://github.com/doxygen/doxygen/issues/5573">5573</a> - Fix a terminating null character after fread in src/filedef.cpp [<a href="http://github.com/doxygen/doxygen/commit/a4003db44dfb624c03b7e0a518e368d3e4b8c1ca">view</a>]</li>
 <li>Bug <a href="https://github.com/doxygen/doxygen/issues/5574">5574</a> - Remove not needed variable initialization in src/classdef.cpp [<a href="http://github.com/doxygen/doxygen/commit/5f01852bbfd3c81320ee4aa8cd45875a80b50ee1">view</a>]</li>
 <li>Bug <a href="https://github.com/doxygen/doxygen/issues/5575">5575</a> - Remove not needed pointer initialization in src/entry.cpp [<a href="http://github.com/doxygen/doxygen/commit/88832b15f1256846b1228ac411d270c6d092a50b">view</a>]</li>
@@ -2182,7 +2182,7 @@ make sure you add the following:
 <h3>New features</h3>
 <ul>
 <li>   Added support for 
-       <a href="http://daringfireball.net/projects/markdown/">Markdown</a>
+       <a href="https://daringfireball.net/projects/markdown/">Markdown</a>
        formatting.
        This is enabled by default, but can be disabled by 
        setting MARKDOWN_SUPPORT to NO. When enabled the following is 
@@ -2803,7 +2803,7 @@ make sure you add the following:
 <li>   id <a href="https://github.com/doxygen/doxygen/issues/3190">3190</a>: dropped support for a4wide paper format for LaTeX, since
        it is on the LaTeX taboo list.</li>
 <li>   id <a href="https://github.com/doxygen/doxygen/issues/3261">3261</a>: Behaviour of CLASS_DIAGRAM=NO in combination with
-       HAVE_DOT=YES, was not propely documented.</li>
+       HAVE_DOT=YES, was not properly documented.</li>
 <li>   id <a href="https://github.com/doxygen/doxygen/issues/3332">3332</a>: Python comments for next class or method could end up in
        code of a method/class when enabling INLINE_SOURCES.</li>
 <li>   id <a href="https://github.com/doxygen/doxygen/issues/3688">3688</a>: Fixed problem handling nested classes in Python.</li>
diff --git a/doc/commands.doc b/doc/commands.doc
index a9973ce..f04b543 100644
--- a/doc/commands.doc
+++ b/doc/commands.doc
@@ -106,6 +106,8 @@ documentation:
 \refitem cmdheaderfile \\headerfile
 \refitem cmdhidecallergraph \\hidecallergraph
 \refitem cmdhidecallgraph \\hidecallgraph
+\refitem cmdhiderefby \\hiderefby
+\refitem cmdhiderefs \\hiderefs
 \refitem cmdhideinitializer \\hideinitializer
 \refitem cmdhtmlinclude \\htmlinclude
 \refitem cmdhtmlonly \\htmlonly
@@ -174,6 +176,8 @@ documentation:
 \refitem cmdsee \\see
 \refitem cmdshort \\short
 \refitem cmdshowinitializer \\showinitializer
+\refitem cmdshowrefby \\showrefby
+\refitem cmdshowrefs \\showrefs
 \refitem cmdsince \\since
 \refitem cmdskip \\skip
 \refitem cmdskipline \\skipline
@@ -214,6 +218,7 @@ documentation:
 \refitem cmdperc \\\%
 \refitem cmdquot \\\"
 \refitem cmdchardot \\\.
+\refitem cmdcolon \:
 \refitem cmddcolon \::
 \refitem cmdpipe \\|
 \refitem cmdndash \\\--
@@ -306,7 +311,7 @@ Structural indicators
   When this command is put in a comment block of a function or method
   and \ref cfg_have_dot "HAVE_DOT" is set to \c YES, then doxygen will
   generate a caller graph for that function (provided the implementation of the
-  function or method calls other documented functions). The caller graph will be
+  function or method is called by other documented functions). The caller graph will be
   generated regardless of the value of \ref cfg_caller_graph "CALLER_GRAPH".
   \note The completeness (and correctness) of the caller graph depends on the
   doxygen code parser which is not perfect.
@@ -333,6 +338,74 @@ Structural indicators
       option \ref cfg_caller_graph "CALLER_GRAPH"
 
 <hr>
+\section cmdshowrefby \\showrefby
+
+  \addindex \\showrefby
+  When this command is put in a comment block of a function, method or variable,
+  then doxygen will generate an overview for that function, method, variable of
+  the, documented, funcions and methods that call / use it.
+  The overview will be generated regardless of the value of
+  \ref cfg_referenced_by_relation "REFERENCED_BY_RELATION".
+  \note The completeness (and correctness) of the overview depends on the
+  doxygen code parser which is not perfect.
+
+  \sa section \ref cmdshowrefs "\\showrefs",
+      section \ref cmdhiderefby "\\hiderefby",
+      section \ref cmdhiderefs "\\hiderefs" and
+      option \ref cfg_referenced_by_relation "REFERENCED_BY_RELATION"
+
+<hr>
+\section cmdhiderefby \\hiderefby
+
+  \addindex \\hiderefby
+  When this command is put in a comment block of a function, method or variable
+  then doxygen will not generate an overview for that function, method or
+  variable of the functions and methods that call / use it.
+  The overview will not be generated regardless of the value of
+  \ref cfg_referenced_by_relation "REFERENCED_BY_RELATION".
+  \note The completeness (and correctness) of the overview depends on the
+  doxygen code parser which is not perfect.
+
+  \sa section \ref cmdshowrefs "\\showrefs",
+      section \ref cmdshowrefby "\\showrefby",
+      section \ref cmdhiderefs "\\hiderefs" and
+      option \ref cfg_referenced_by_relation "REFERENCED_BY_RELATION"
+
+<hr>
+\section cmdshowrefs \\showrefs
+
+  \addindex \\showrefs
+  When this command is put in a comment block of a function or method,
+  then doxygen will generate an overview for that function or method of the 
+  functions and methods that call it.
+  The overview will be generated regardless of the value of
+  \ref cfg_references_relation "REFERENCES_RELATION".
+  \note The completeness (and correctness) of the overview depends on the
+  doxygen code parser which is not perfect.
+
+  \sa section \ref cmdshowrefby "\\showrefby",
+      section \ref cmdhiderefby "\\hiderefby",
+      section \ref cmdhiderefs "\\hiderefs" and
+      option \ref cfg_references_relation "REFERENCES_RELATION"
+
+<hr>
+\section cmdhiderefs \\hiderefs
+
+  \addindex \\hiderefs
+  When this command is put in a comment block of a function or method
+  and then doxygen will not generate an overview for that function or method of
+  the functions and methods that call it.
+  The overview will not be generated regardless of the value of
+  \ref cfg_references_relation "REFERENCES_RELATION".
+  \note The completeness (and correctness) of the overview depends on the
+  doxygen code parser which is not perfect.
+
+  \sa section \ref cmdshowrefs "\\showrefs",
+      section \ref cmdshowrefby "\\showrefby",
+      section \ref cmdhiderefby "\\hiderefby" and
+      option \ref cfg_references_relation "REFERENCES_RELATION"
+
+<hr>
 \section cmdcategory \\category <name> [<header-file>] [<header-name>]
 
   \addindex \\category
@@ -442,14 +515,15 @@ Structural indicators
   \endlatexonly
 
 </p><hr>
-\section cmdexample \\example <file-name>
+\section cmdexample \\example[{lineno}] <file-name>
 
   \addindex \\example
   Indicates that a comment block contains documentation for a source code
-  example. The name of the source file is \<file-name\>. The text of
-  this file will be included in the documentation, just after the
-  documentation contained in the comment block. All examples are placed
-  in a list. The source code is scanned for documented members and classes.
+  example. The name of the source file is \<file-name\>.
+  The contents of this file will be included in the documentation, just after the
+  documentation contained in the comment block.
+  You can add option `{lineno}` to enable line numbers for the example if desired.
+  All examples are placed in a list. The source code is scanned for documented members and classes.
   If any are found, the names are cross-referenced with the documentation.
   Source files or directories can be specified using the
   \ref cfg_example_path "EXAMPLE_PATH"
@@ -1887,7 +1961,7 @@ Commands to create links
 \section cmdaddindex \\addindex (text)
 
   \addindex \\addindex
-  This command adds (text) to the \LaTeX index.
+  This command adds (text) to the \LaTeX , DocBook and RTF index.
 
 <hr>
 \section cmdanchor \\anchor <word>
@@ -2033,7 +2107,7 @@ Make sure you have first read \ref intro "the introduction".
   \addindex \\tableofcontents
   Creates a table of contents at the top of a page, listing all
   sections and subsections in the page. The `option` can be `HTML` or `LaTeX`
-  or `XML`. When a `level` is specified this means the maximum nesting level
+  or `XML` or `DocBook`. When a `level` is specified this means the maximum nesting level
   that is shown. The value of `level` should be in the range 1..5, values outside
   this range are considered to be 5. In case no `level` is specified `level` is
   set to 5 (show all)
@@ -2151,16 +2225,12 @@ Commands for displaying examples
   for the corresponding \mbox{\LaTeX} documentation that is generated by doxygen.
   \endlatexonly
 
-  Alternatively, the \ref cmdsnippet "\\snippet" command can be used to
-  include only a fragment of a source file. For this to work the
-  fragment has to be marked.
-
   \sa sections \ref cmdline "\\line", \ref cmdskip "\\skip",
                \ref cmdskipline "\\skipline", \ref cmduntil "\\until", and
                \ref cmdinclude "\\include".
 
 </p><hr>
-\section cmdinclude \\include <file-name>
+\section cmdinclude \\include[{lineno|doc}] <file-name>
 
   \addindex \\include
   This command can be used to include a source file as a block of code.
@@ -2194,33 +2264,38 @@ Commands for displaying examples
   \note Doxygen's special commands do not work inside blocks of code.
   It is allowed to nest C-style comments inside a code block though.
 
+  You can add option `{lineno}` to enable line numbers for the included code if desired.
+
+  You can add option `{doc}` to treat the file as documentation rather than code.
+
+  \note Some that when using the `{doc}` option,
+       commands like \ref cmdcond "\\cond" and \ref cmdif "\\if" don't work with
+       this command due to the moment of parsing.
+
+  \note The included documentation should not have comment signs in it as they will appear
+       in the documentation as well.
+
   \sa sections \ref cmdexample "\\example", \ref cmddontinclude "\\dontinclude",
-      \ref cmdverbatim "\\verbatim" and \ref cmdincludedoc "\\includedoc".
+      \ref cmdverbatim "\\verbatim", \ref cmdincludedoc "\\includedoc", and
+      \ref cmdsnippet "\\snippet".
 
 <hr>
 \section cmdincludelineno \\includelineno <file-name>
 
   \addindex \\includelineno
-  This command works the same way as \ref cmdinclude "\\include", but will add line
-  numbers to the included file.
+  This command is obsolete and is still supported for backward compatibility reasons,
+  it works the same way as \ref cmdinclude "\\include{lineno}"
 
-  \sa sections \ref cmdinclude "\\include" and \ref cmdsnippetlineno "\\snippetlineno".
+  \sa sections \ref cmdinclude "\\include{lineno}".
 
 <hr>
 \section cmdincludedoc \\includedoc <file-name>
 
   \addindex \\includedoc
-  This command works the same way as \ref cmdinclude "\\include", but it will include
-  the content of the file as if it were at the place where this command is called.
-  The result is that the content is parsed by doxygen and placed in the documentation.
-
-  \note Some commands like \ref cmdcond "\\cond" and \ref cmdif "\\if" don't work with
-        this command due to the moment of parsing.
-
-  \note The included documentation should not have comment signs in it as they will appear
-        in the documentation as well.
+  This command is obsolete and is still supported for backward compatibility reasons,
+  it works the same way as \ref cmdinclude "\\include{doc}"
 
-  \sa section \ref cmdinclude "\\include".
+  \sa section \ref cmdinclude "\\include{doc}".
 
 <hr>
 \section cmdline \\line ( pattern )
@@ -2278,7 +2353,7 @@ Commands for displaying examples
   See section \ref cmddontinclude "\\dontinclude" for an example.
 
 <hr>
-\section cmdsnippet \\snippet <file-name> ( block_id )
+\section cmdsnippet \\snippet[{lineno|doc}] <file-name> ( block_id )
 
  \addindex \\snippet
  Where the \ref cmdinclude "\\include" command can be used to include
@@ -2321,34 +2396,37 @@ Commands for displaying examples
  Note also that the [block_id] markers should appear exactly twice in the
  source file.
 
+ You can add option `{lineno}` to enable line numbers for the snippet if desired.
+
+ You can add option `{doc}` to treat the file as documentation rather than code.
+
+ \note Some that when using the `{doc}` option,
+       commands like \ref cmdcond "\\cond" and \ref cmdif "\\if" don't work with
+       this command due to the moment of parsing.
+
+ \note The included documentation should not have comment signs in it as they will appear
+       in the documentation as well.
+
  see section \ref cmddontinclude "\\dontinclude" for an alternative way
  to include fragments of a source file that does not require markers.
 
- \sa section \ref cmdsnippetdoc "\\snippetdoc" and \ref cmdsnippetlineno "\\snippetlineno".
 <hr>
 \section cmdsnippetlineno \\snippetlineno <file-name> ( block_id )
 
   \addindex \\snippetlineno
-  This command works the same way as \ref cmdsnippet "\\snippet", but will add line
-  numbers to the included snippet.
+  This command is obsolete and is still supported for backward compatibility reasons,
+  it works the same way as \ref cmdsnippet "\\snippet{lineno}"
 
-  \sa sections \ref cmdsnippet "\\snippet" and \ref cmdincludelineno "\\includelineno".
+  \sa sections \ref cmdsnippet "\\snippet{lineno}"
 
 <hr>
 \section cmdsnippetdoc \\snippetdoc <file-name> ( block_id )
 
   \addindex \\snippetdoc
-  This command works the same way as \ref cmdsnippet "\\snippet", but it will include
-  the content of the file between the `block-id`s as if it were at the place where this command is called.
-  The result is that the content is parsed by doxygen and placed in the documentation.
-
-  \note Some commands like \ref cmdcond "\\cond" and \ref cmdif "\\if" don't work with
-        this command due to the moment of parsing.
-
-  \note The included documentation should not have comment signs in it as they will appear
-        in the documentation as well.
+  This command is obsolete and is still supported for backward compatibility reasons,
+  it works the same way as \ref cmdsnippet "\\snippet{doc}"
 
-  \sa section \ref cmdsnippet "\\snippet" and \ref cmdincludedoc "\\includedoc".
+  \sa section \ref cmdsnippet "\\snippet{doc}" and \ref cmdinclude "\\include{doc}".
 
 <hr>
 \section cmduntil \\until ( pattern )
@@ -2603,7 +2681,7 @@ only copy the detailed documentation, not the brief description.
 
   \addindex \\docbookonly
   Starts a block of text that will be verbatim included in the
-  generated docbook documentation only. The block ends with a
+  generated DocBook documentation only. The block ends with a
   \ref cmdenddocbookonly "\\enddocbookonly" command.
 
   \sa section \ref cmdmanonly "\\manonly", 
@@ -3077,7 +3155,7 @@ class Receiver
   spaces. The quotes are stripped before the caption is displayed.
 
   The fourth argument is also optional and can be used to specify the
-  width or height of the image. This can be useful for \LaTeX or docbook output
+  width or height of the image. This can be useful for \LaTeX or DocBook output
   (i.e. format=<code>latex</code> or format=<code>docbook</code>).
   \anchor image_sizeindicator \par Size indication
   The \c sizeindication can specify the width or height to be used (or a combination).
@@ -3279,7 +3357,7 @@ class Receiver
   \addindex \\\@
   This command writes an at-sign (\c \@) to the output.
   The at-sign has to be escaped in some cases
-  because doxygen uses it to detect JavaDoc commands.
+  because doxygen uses it to detect Javadoc commands.
 
 <hr>
 \section cmdtilde \\~[LanguageId]
@@ -3361,6 +3439,14 @@ class Receiver
   the start of a line.
 
 <hr>
+\section cmdcolon \:
+
+  \addindex \\:
+  This command writes a single colon (\c \:) to the output. This
+  character sequence has to be escaped in some cases, because it is used
+  to define `emoji` see also \ref emojisup "Emoji support".
+
+<hr>
 \section cmddcolon \\::
 
   \addindex \\::
@@ -3423,4 +3509,3 @@ Go to the <a href="htmlcmds.html">next</a> section or return to the
 \endhtmlonly
 
 */
-
diff --git a/doc/custcmd.doc b/doc/custcmd.doc
index acc0224..02805da 100644
--- a/doc/custcmd.doc
+++ b/doc/custcmd.doc
@@ -44,6 +44,11 @@ Note that you can put `\n`'s in the value part of an alias to insert newlines
 (in the resulting output). You can put `^^` in the value part of an alias to
 insert a newline as if a physical newline was in the original file.
 
+Note when you need a literal `{` or `}` or `,` in the value part of an alias you have to
+escape them by means of a backslash (`\`), this can lead to conflicts with the
+commands \c \\{ and \c \\} for these it is advised to use the version \c @@{ and \c @@} or
+use a double escape (\c \\\\{ and \c \\\\})
+
 Also note that you can redefine existing special commands if you wish.
 
 Some commands, such as \ref cmdxrefitem "\\xrefitem" are designed to be used in
diff --git a/doc/docblocks.doc b/doc/docblocks.doc
index f02e55b..a9cb05a 100644
--- a/doc/docblocks.doc
+++ b/doc/docblocks.doc
@@ -55,7 +55,7 @@ used to provide tooltips at places where an item is referenced.
 
 There are several ways to mark a comment block as a detailed description:
 <ol>
-<li> You can use the JavaDoc style, which consist of a C-style comment
+<li> You can use the Javadoc style, which consist of a C-style comment
 block starting with two *'s, like this:
 
 \verbatim
@@ -143,7 +143,7 @@ Here is an example:
 
 <li>If \ref cfg_javadoc_autobrief "JAVADOC_AUTOBRIEF" is set to \c YES 
     in the configuration file, 
-    then using JavaDoc style comment
+    then using Javadoc style comment
     blocks will automatically start a brief description which ends at the
     first dot followed by a space or new line. Here is an example:
 
@@ -299,8 +299,8 @@ sentence of the detailed descriptions
 tag to \c NO). Both the brief and the detailed descriptions are optional 
 for the Qt style. 
 
-By default a JavaDoc style documentation block behaves the same way as a
-Qt style documentation block. This is not according the JavaDoc specification
+By default a Javadoc style documentation block behaves the same way as a
+Qt style documentation block. This is not according the Javadoc specification
 however, where the first sentence of the documentation block is automatically
 treated as a brief description. To enable this behavior you should set
 \ref cfg_javadoc_autobrief "JAVADOC_AUTOBRIEF" to YES in the configuration
@@ -312,7 +312,7 @@ Here is an example:
 \endverbatim
 
 Here is the same piece of code as shown above, this time documented using the 
-JavaDoc style and \ref cfg_javadoc_autobrief "JAVADOC_AUTOBRIEF" set to YES:
+Javadoc style and \ref cfg_javadoc_autobrief "JAVADOC_AUTOBRIEF" set to YES:
 \include jdstyle.cpp
  \htmlonly
  </p>
@@ -348,7 +348,7 @@ duplication of information. So in practice you should \e avoid the use of
 structural commands \e unless other requirements force you to do so.
 
 Structural commands (like \ref cmd_intro "all other commands") start with a backslash 
-(<tt>\\</tt>), or an at-sign (<tt>\@</tt>) if you prefer JavaDoc style, 
+(<tt>\\</tt>), or an at-sign (<tt>\@</tt>) if you prefer Javadoc style, 
 followed by a command name and one or more parameters.
 For instance, if you want to document the class \c Test in the example
 above, you could have also put the following documentation block somewhere
@@ -632,7 +632,7 @@ and is ideal for a short description.
 For longer descriptions you often will find the 
 need for some more structure, like a block of verbatim text, a list, or a 
 simple table. For this doxygen supports the 
-<a href="http://daringfireball.net/projects/markdown/syntax">Markdown</a> 
+<a href="https://daringfireball.net/projects/markdown/syntax">Markdown</a> 
 syntax, including parts of the
 <a href="https://michelf.ca/projects/php-markdown/extra/">Markdown Extra</a>
 extension. 
@@ -648,8 +648,9 @@ forms of additional markup on top of Markdown formatting.
 
 1. <a href="https://en.wikipedia.org/wiki/Javadoc">Javadoc</a> like markup.
    See \ref commands for a complete overview of all commands supported by doxygen.
-2. <a href="https://en.wikipedia.org/wiki/C_Sharp_(programming_language)#XML_documentation_system">XML</a> markup
-   as specified in the C# standard. See \ref xmlcmds for the XML commands supported by doxygen.
+2. <a href="https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/xmldoc/recommended-tags-for-documentation-comments">XML</a> markup
+   as specified in the <a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c042926_ISO_IEC_23270_2006(E).zip">C# standard</a>.
+   See \ref xmlcmds for the XML commands supported by doxygen.
 
 If this is still not enough doxygen also supports a \ref htmlcmds "subset" of 
 the <a href="https://en.wikipedia.org/wiki/HTML">HTML</a> markup language.
diff --git a/doc/doxygen.1 b/doc/doxygen.1
index 1deb7b6..a9c6b38 100644
--- a/doc/doxygen.1
+++ b/doc/doxygen.1
@@ -3,7 +3,7 @@
 doxygen \- documentation system for various programming languages
 .SH DESCRIPTION
 Doxygen is a documentation system for C++, C, Java, Objective-C, IDL
-(Corba and Microsoft flavors) and to some extent PHP, C#, and D.
+(Corba and Microsoft flavors), Fortran, Python, VHDL and to some extent PHP, C#, and D.
 .PP
 You can use doxygen in a number of ways:
 .TP
@@ -25,7 +25,7 @@ If - is used for configName doxygen will read from standard input.
 .TP
 4) Use doxygen to generate a template file controlling the layout of the generated documentation:
 .IP
-doxygen -l layoutFileName.xml
+doxygen -l [layoutFileName.xml]
 .TP
 5) Use doxygen to generate a template style sheet file for RTF, HTML or Latex.
 .TP
@@ -41,6 +41,10 @@ LaTeX: doxygen \fB\-w\fR latex headerFile footerFile styleSheetFile [configFile]
 .TP
 RTF:
 doxygen \fB\-e\fR rtf extensionsFile
+.TP
+7) Use doxygen to compare the used configuration file with the template configuration file
+.TP
+doxygen \fB\-x\fR [configFile]
 .PP
 If \fB\-s\fR is specified the comments in the config file will be omitted.
 If configName is omitted `Doxyfile' will be used as a default.
diff --git a/doc/doxygen_manual.tex b/doc/doxygen_manual.tex
index 95e1ed6..e749560 100644
--- a/doc/doxygen_manual.tex
+++ b/doc/doxygen_manual.tex
@@ -121,6 +121,7 @@ Written by Dimitri van Heesch\\[2ex]
 \chapter{Special Commands}\label{commands}\hypertarget{commands}{}\input{commands}
 \chapter{HTML commands}\label{htmlcmds}\hypertarget{htmlcmds}{}\input{htmlcmds}
 \chapter{XML commands}\label{xmlcmds}\hypertarget{xmlcmds}{}\input{xmlcmds}
+\chapter{Emoji support}\label{emojisup}\hypertarget{emojisup}{}\input{emojisup}
 \part{Developers Manual}
 \chapter{Doxygen's internals}\label{arch}\hypertarget{arch}{}\input{arch}
 \chapter{Perl Module Output format}\label{perlmod}\hypertarget{perlmod}{}\input{perlmod}
diff --git a/doc/doxyindexer.1 b/doc/doxyindexer.1
index ae4b282..b0d46d0 100644
--- a/doc/doxyindexer.1
+++ b/doc/doxyindexer.1
@@ -3,7 +3,7 @@
 doxyindexer \- creates a search index from raw search data
 .SH SYNOPSIS
 .B doxyindexer
-[\fI-o output_dir\fR] \fIsearchdata.xml \fR[\fIsearchdata2.xml\fR...] ]
+[\fI-o output_dir\fR] \fIsearchdata.xml \fR[\fIsearchdata2.xml\fR...]
 .SH DESCRIPTION
 Generates a search index called \fBdoxysearch.db\fR from one or more
 search data files produced by doxygen. Use
diff --git a/doc/doxysearch.1 b/doc/doxysearch.1
index a00124f..a26107b 100644
--- a/doc/doxysearch.1
+++ b/doc/doxysearch.1
@@ -2,10 +2,10 @@
 .SH NAME
 doxysearch.cgi \- search engine used for searching in doxygen documentation.
 .SH SYNOPSIS
-.B doxyindexer.cgi
+.B doxysearch.cgi
 .SH DESCRIPTION
 CGI binary that is used by doxygen generated HTML output to search for words. 
 The tool uses the search index called \fBdoxysearch.db\fR produced by 
 doxyindexer. 
 .SH SEE ALSO
-doxygen(1), doxysearch(1), doxywizard(1).
+doxygen(1), doxyindexer(1), doxywizard(1).
diff --git a/doc/emojisup.doc b/doc/emojisup.doc
new file mode 100644
index 0000000..75a90fb
--- /dev/null
+++ b/doc/emojisup.doc
@@ -0,0 +1,166 @@
+/******************************************************************************
+ *
+ * 
+ *
+ * Copyright (C) 1997-2018 by Dimitri van Heesch.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation under the terms of the GNU General Public License is hereby 
+ * granted. No representations are made about the suitability of this software 
+ * for any purpose. It is provided "as is" without express or implied warranty.
+ * See the GNU General Public License for more details.
+ *
+ * Documents produced by Doxygen are derivative works derived from the
+ * input used in their production; they are not affected by this license.
+ *
+ */
+/*! \page emojisup Emoji support
+
+The [Unicode consortium](http://www.unicode.org/) has defined a set of
+[emoji](https://en.wikipedia.org/wiki/Emoji) with the corresponding unicode
+sequences and a so called "CLDR short name". The current version a v11.0 and can be found at
+[Full Emoji List, v11.0](https://unicode.org/emoji/charts/full-emoji-list.html) furthermore there is the list with 
+[Full Emoji Modifier Sequences, v11.0](http://www.unicode.org/emoji/charts/full-emoji-modifiers.html).
+
+A common way to denote an emoji is by means of `:<text>:`,
+doxygen supports the emoji as mentioned in the above mentioned unicode emoji lists in this way
+by means of the "CLDR short name" with the exception that in case a colon (`:`) is in the
+"CLDR short name" this colon has to be removed.
+Furthermore doxygen supports the list of emoji as used by github (based on the list 
+https://api.github.com/emojis). In this list also a reference is given to the unicode codes (just the
+first and last) and these unicodes are mapped onto the official unicode sequences.
+In case the "CLDR short name" and the "github name" are the same the reference from the 
+"CLDR short name" has precedence.
+
+Implementation
+
+For the different doxygen output types there is an output defined:
+- Unicode code sequence, the actual representation is depending on the possibilities of the fonts loaded:
+  - HTML
+  - XML
+  - DocBook
+  - RTF, converted to UTF-16 representation.
+- Image
+  - \LaTeX, in case the image can be found (see \ref emojiimage "Emoji image retrieval") otherwise the plain emoji text (i.e. `:<text>:`) is displayed
+- plain emoji text (i.e. `:<text>:`)
+  - man
+  - perl
+
+\anchor emojiimage Emoji image retrieval
+
+In the  lists 
+[Full Emoji List, v11.0](https://unicode.org/emoji/charts/full-emoji-list.html) and
+[Full Emoji Modifier Sequences, v11.0](http://www.unicode.org/emoji/charts/full-emoji-modifiers.html).
+define images for the different vendors. These images can be retrieved by means of the following procedure (based on the code from Henning Pohl, https://github.com/henningpohl/latex-emoji):
+\code{.py}
+from bs4 import BeautifulSoup
+import base64
+import os
+import requests
+
+# http://www.unicode.org/emoji/charts/index.html
+# http://www.unicode.org/emoji/charts/full-emoji-list.html
+PAGE_URL = 'http://www.unicode.org/emoji/charts/full-emoji-list.html'
+PAGE_URL_SKIN = 'http://www.unicode.org/emoji/charts/full-emoji-modifiers.html'
+PAGE = 'full-emoji-list.html'
+PAGE_SKIN = 'full-emoji-modifiers.html'
+
+
+def get_header_names(header):
+    cols = header.find_all('th')
+    cols = [c.get_text() for c in cols]
+    cols = [c.replace('*','') for c in cols]
+    cols = [c.lower() for c in cols]
+    return cols
+
+def extract_image(column):
+    if 'miss' in column['class']:
+        return None
+
+    if 'miss7' in column['class']:
+        return None
+
+    data = column.img['src']
+    data_start = data.find("base64,")
+    if data_start == -1:
+        return None
+    
+    data = base64.b64decode(data[data_start + len("base64,"):])
+    return data
+
+def save_image(folder, imgSrc, filename):
+    if os.path.exists(folder) is False:
+        os.mkdir(folder)
+
+    filename = os.path.join(folder, filename)
+    if os.path.exists(filename):
+        return
+
+    img = extract_image(imgSrc)
+    if img is not None:
+        with open(filename, 'wb') as out:
+            out.write(img)
+
+def scrape(page_url, page):
+    # Possibilities to obtain the basic data:
+    # - use request.get directly
+    soup = BeautifulSoup(requests.get(page_url).text, "html5lib")
+    # - download file (e.g. with wget http://www.unicode.org/emoji/charts/full-emoji-list.html)
+    # with open(page) as fp:
+    #     soup = BeautifulSoup(fp,"html5lib")
+
+    table = soup('table')[0]
+
+    # for version 11.0
+    # first row: smileys
+    # second row: face smileys
+    # third row: row with vendors, i.e. the one we want
+    header = table.find_all('tr')[2]
+    keys = get_header_names(header)
+
+    for row in header.find_next_siblings('tr'):
+        fields = {k:c for k, c in zip(keys, row.find_all('td')) }
+        if 'code' not in fields:
+            continue
+
+        codes = fields['code'].text.replace('U+', '').split(' ')
+        filename = "-".join(codes) + ".png"
+
+        save_image('ios', fields['appl'], filename)
+        save_image('android', fields['goog'], filename)
+        save_image('twitter', fields['twtr'], filename)
+        save_image('windows', fields['wind'], filename)
+        save_image('one', fields['one'], filename)
+        save_image('facebook', fields['fb'], filename)
+        save_image('samsung', fields['sams'], filename)
+        #save_image('gmail', fields['gmail'], filename)
+        #save_image('softbank', fields['sb'], filename)
+        #save_image('docomo', fields['dcm'], filename)
+        #save_image('kddi', fields['kddi'], filename)
+        #save_image('bw', fields['chart'], filename)
+
+if __name__ == '__main__':
+    scrape(PAGE_URL, PAGE)
+    scrape(PAGE_URL_SKIN, PAGE_SKIN)
+\endcode
+This results in a number of directories with the supported images. By means of the doxygen configuration parameter
+\ref cfg_latex_emoji_directory "LATEX_EMOJI_DIRECTORY" the requested directory can be selected.
+
+It is also possible to use images from other sources or mix images from different sources, the only requirement is that the filename represents the unicode of the emoji. e.g. if we have the emoji <tt>\:grinning face with big eyes\:</tt> (also known as <tt>\:smiley\:</tt>) the coresponding unicode is `U+1F603` and the name of the file is `1F603.png`.<br>
+For a more complex emoji like <tt>\:keycap 1\:</tt> (also known as <tt>\:one\:</tt>) the coresponding unicode sequence is `U+0031U+FE0FU+20E3` and the name of the file is `0031-FE0F-20E3.png`.
+
+
+Note that when you want to use a colon (`:`) in your text it might be necessary to escape the colon (see \ref cmdcolon "\\:") as it might conflict with a, possible, emoji sequence.
+  
+
+For a overview of the supported emoji one can issue the comand:<br>
+`doxygen.exe -f emoji <outputFileName>`
+
+
+\htmlonly
+Go to the <a href="langhowto.html">next</a> section or return to the
+ <a href="index.html">index</a>.
+\endhtmlonly
+
+*/
+ 
diff --git a/doc/faq.doc b/doc/faq.doc
index e9c93d8..f48e109 100644
--- a/doc/faq.doc
+++ b/doc/faq.doc
@@ -216,7 +216,7 @@ If you don't mind spending some time on it, there are several options:
 - If the grammar of X is somewhat different than you can write an input
   filter that translates X into something similar enough to C/C++ for
   doxygen to understand (this approach is taken for VB, Object Pascal, and
-  Javascript, see http://www.stack.nl/~dimitri/doxygen/download.html#helpers).
+  Javascript, see http://www.doxygen.org/download.html#helpers).
 - If the grammar is completely different one could write a parser for X and 
   write a backend that produces a similar syntax tree as is done by 
   \c src/scanner.l (and also by \c src/tagreader.cpp while reading tag files).
diff --git a/doc/features.doc b/doc/features.doc
index f6aa7c1..8b19898 100644
--- a/doc/features.doc
+++ b/doc/features.doc
@@ -33,7 +33,7 @@
 <li>Supports documentation of files, namespaces, packages, classes, 
     structs, unions, templates, variables, functions, typedefs, enums and 
     defines. 
-<li>JavaDoc (1.1), qdoc3 (partially), and ECMA-334 (C# spec.) compatible.
+<li>Javadoc (1.1), qdoc3 (partially), and ECMA-334 (C# spec.) compatible.
 <li>Comes with a GUI frontend (Doxywizard) to ease editing the options and 
     run doxygen. The GUI is available on Windows, Linux, and MacOSX.
 <li>Automatically generates class and collaboration diagrams in HTML (as clickable 
@@ -100,7 +100,7 @@
 Although doxygen can now be used in any project written in a language that is 
 supported by doxygen, initially it was specifically designed to be used for projects 
 that make use of Qt Software's 
-<A HREF="http://qt-project.org/">Qt toolkit</A>. I have tried to 
+<A HREF="https://www.qt.io/developers/">Qt toolkit</A>. I have tried to 
 make doxygen `Qt-compatible'. That is: Doxygen can read the documentation contained in 
 the Qt source code and create a class browser that looks quite similar to the 
 one that is generated by Qt Software. Doxygen understands the C++ extensions 
diff --git a/doc/htmlcmds.doc b/doc/htmlcmds.doc
index b8324f8..d483237 100644
--- a/doc/htmlcmds.doc
+++ b/doc/htmlcmds.doc
@@ -83,6 +83,8 @@ of a HTML tag are passed on to the HTML output only
 <li><tt>\</SMALL\></tt> Ends a <tt>\<SMALL\></tt> section.
 <li><tt>\<SPAN></tt>   Starts an inline text fragment with a specific style (HTML only)
 <li><tt>\</SPAN></tt>  Ends an inline text fragment with a specific style (HTML only)
+<li><tt>\<STRIKE\></tt> Starts a section of strike through text.
+<li><tt>\</STRIKE\></tt> Ends a section of strike through text.
 <li><tt>\<STRONG\></tt> Starts a section of bold text.
 <li><tt>\</STRONG\></tt> Ends a section of bold text.
 <li><tt>\<SUB\></tt>   Starts a piece of text displayed in subscript.
@@ -101,6 +103,8 @@ of a HTML tag are passed on to the HTML output only
 <li><tt>\</TT\></tt>   Ends a <tt>\<TT\></tt> section.
 <li><tt>\<KBD\></tt>   Starts a piece of text displayed in a typewriter font.
 <li><tt>\</KBD\></tt>  Ends a <tt>\<KBD\></tt> section.
+<li><tt>\<U\></tt> Starts a section of underlined text.
+<li><tt>\</U\></tt> Ends a section of underlined text.
 <li><tt>\<UL\></tt>    Starts an unnumbered item list.
 <li><tt>\</UL\></tt>   Ends an unnumbered item list.
 <li><tt>\<VAR\></tt>   Starts a piece of text displayed in an italic font.
diff --git a/doc/index.doc b/doc/index.doc
index 5bb7b2b..9afe624 100644
--- a/doc/index.doc
+++ b/doc/index.doc
@@ -102,6 +102,8 @@ The second part forms a reference manual:
               can be used within the documentation.
 <li>Section \ref xmlcmds shows an overview of the C# style XML commands that
               can be used within the documentation.
+<li>Section \ref emojisup shows an introduction how emoji can be used within
+              the documentation.
 </ul>
 
 The third part provides information for developers:
@@ -119,7 +121,7 @@ The third part provides information for developers:
 \addindex GPL
 
 Copyright &copy; 1997-2016 by 
-<a href="mailto:dimitri@stack.nl">Dimitri van Heesch</a>.<p>
+<a href="mailto:doxygen@gmail.com">Dimitri van Heesch</a>.<p>
 
 Permission to use, copy, modify, and distribute this software and its
 documentation under the terms of the GNU General Public License is hereby 
@@ -143,7 +145,7 @@ of real-life projects using doxygen.
 These are part of a larger
 <a href="http://www.doxygen.org/projects.html">list of projects</a> 
 that use doxygen.
-If you know other projects, let <a href="mailto:dimitri@stack.nl?subject=New%20project%20using%20Doxygen">me</a> 
+If you know other projects, let <a href="mailto:doxygen@gmail.com?subject=New%20project%20using%20Doxygen">me</a> 
 know and I'll add them. 
 
 <h2>Future work</h2>
diff --git a/doc/install.doc b/doc/install.doc
index 497a0c0..d64b259 100644
--- a/doc/install.doc
+++ b/doc/install.doc
@@ -36,6 +36,7 @@ following to build the executable:
     \addindex make
     \addindex strip
     \addindex python
+<li>You need \c python (version 2.6 or higher, see https://www.python.org).
 <li>In order to generate a \c Makefile for your platform, you need 
     <a href="https://cmake.org/">cmake</a> version 2.8.12 or later.
     \addindex cmake
@@ -46,9 +47,9 @@ tools should be installed.
 
 <ul>
 <li>Qt Software's GUI toolkit 
-    <a href="http://qt-project.org/">Qt</A>
+    <a href="https://www.qt.io/developers/">Qt</A>
     \addindex Qt
-    version 4.3 or higher (but currently, Qt 5.x is not yet supported).
+    version 4.3 or higher (including Qt 5).
     This is needed to build the GUI front-end doxywizard. 
 <li>A \LaTeX distribution: for instance
     <a href="http://www.tug.org/interest.html#free">TeX Live</a>
@@ -151,6 +152,7 @@ standard installation procedure that is required for these packages.
 
 From version 1.8.10 onwards, build files need to be generated by cmake.
 cmake can be downloaded from https://cmake.org/download/
+\addindex cmake
 
 At the moment only the express version of Visual Studio 2013 is tested,
 but other version might also work.
@@ -160,9 +162,12 @@ Alternatively, you can compile doxygen
 <a href="https://en.wikipedia.org/wiki/Cygwin">Cygwin</a>
 or <a href="http://www.mingw.org/">MinGW</a>.
 
+\addindex flex
+\addindex bison
 The next step is to install modern versions of \c bison and \c flex
 (see https://sourceforge.net/projects/winflexbison/. After installation and adding them to
 your `path` rename `win_flex.exe` to `flex.exe` and `win_bison.exe` to `bison.exe`)
+\addindex python
 Furthermore you have to install \c python (version 2.6 or higher, see https://www.python.org).
 These packages are needed during the compilation process.
 
@@ -174,7 +179,7 @@ cd c:\tools
 tar zxvf doxygen-x.y.z.src.tar.gz
 \endverbatim
 to unpack the sources (you can obtain \c tar from e.g. http://gnuwin32.sourceforge.net/packages.html).
-Alternatively you can use an unpack program, like 7-Zip (see http://www.7-zip.org)
+Alternatively you can use an unpack program, like 7-Zip (see https://www.7-zip.org/)
 or use the build in unpack feature of modern Windows systems).
 
 Now your environment is setup to generate the required project files for \c doxygen.
@@ -186,8 +191,8 @@ cd build
 cmake -G "Visual Studio 12 2013" ..
 \endverbatim
 
-Note that compiling Doxywizard currently requires Qt version 4
-(see http://qt-project.org/).
+Note that compiling Doxywizard requires Qt 4.3 or newer
+(see https://www.qt.io/developers/).
 
 Also read the next section for additional tools you may need to install to run
 doxygen with certain features enabled.
@@ -206,12 +211,12 @@ If you want to produce compressed HTML files (see \ref
 cfg_generate_htmlhelp "GENERATE_HTMLHELP") in the configuration file, then 
 you need the Microsoft HTML help workshop. 
 You can download it from 
-<a href="http://www.microsoft.com/en-us/download/details.aspx?id=21138">Microsoft</a>.
+<a href="https://www.microsoft.com/en-us/download/details.aspx?id=21138">Microsoft</a>.
 
 If you want to produce Qt Compressed Help files (see \ref 
 cfg_qhg_location "QHG_LOCATION") in the configuration file, then 
 you need qhelpgenerator which is part of Qt. 
-You can download Qt from <a href="http://qt-project.org/downloads">Qt Software Downloads</a>.
+You can download Qt from <a href="https://www.qt.io/download">Qt Software Downloads</a>.
 
 In order to generate PDF output or use scientific formulas you will also need to
 install <a href="https://en.wikipedia.org/wiki/LaTeX">LaTeX</a> and 
@@ -219,7 +224,7 @@ install <a href="https://en.wikipedia.org/wiki/LaTeX">LaTeX</a> and
 
 For \LaTeX a number of distributions exists. Popular ones that should work with
 doxygen are <a href="https://miktex.org/">MikTex</a> 
-and <a href="http://www.tug.org/protext/">proTeXt</a>.
+and <a href="https://www.tug.org/protext/">proTeXt</a>.
 
 Ghostscript can be <a href="https://sourceforge.net/projects/ghostscript/">downloaded</a> 
 from Sourceforge.
diff --git a/doc/maintainers.txt b/doc/maintainers.txt
index 3fa4fff..7ea40ac 100644
--- a/doc/maintainers.txt
+++ b/doc/maintainers.txt
@@ -50,10 +50,10 @@ Poul-Erik Hansen: pouhan at gnotometrics dot dk
 Erik Søe Sørensen: eriksoe+doxygen at daimi dot au dot dk
 
 TranslatorDutch
-Dimitri van Heesch: dimitri at stack dot nl
+Dimitri van Heesch: doxygen at gmail dot com
 
 TranslatorEnglish
-Dimitri van Heesch: dimitri at stack dot nl
+Dimitri van Heesch: doxygen at gmail dot com
 
 TranslatorEsperanto
 Ander Martínez: ander dot basaundi at gmail dot com
diff --git a/doc/markdown.doc b/doc/markdown.doc
index 92612ca..5edbaf9 100644
--- a/doc/markdown.doc
+++ b/doc/markdown.doc
@@ -41,7 +41,7 @@ the extensions that doxygen supports.
 Finally section \ref markdown_dox discusses some specifics for doxygen's
 implementation of the Markdown standard.
 
-[markdown]: http://daringfireball.net/projects/markdown/ 
+[markdown]: https://daringfireball.net/projects/markdown/ 
 [mdextra]:  https://michelf.ca/projects/php-markdown/extra/
 [github]:   https://github.github.com/github-flavored-markdown/
 
@@ -173,7 +173,18 @@ Examples:
 *    __double underscores__
 
 See section \ref mddox_emph_spans for more info how doxygen handles
-emphasis spans slightly different than standard Markdown.
+emphasis / strikethrough spans slightly different than standard / Markdown GitHub Flavored Markdown.
+
+\subsection md_strikethrough Strikethrough
+
+To strikethrough a text fragment you start and end the fragment with two tildes.
+
+Examples:
+
+*    ~~double tilde~~
+
+See section \ref mddox_emph_spans for more info how doxygen handles
+emphasis / strikethrough spans slightly different than standard Markdown / GitHub Flavored Markdown.
 
 \subsection md_codespan code spans
 
@@ -567,22 +578,22 @@ For Item1 the indentation is 4 (when treating the list marker as whitespace),
 so the next paragraph "More text..." starts at the same indentation level 
 and is therefore not seen as a code block.
 
-\subsection mddox_emph_spans Emphasis limits
+\subsection mddox_emph_spans Emphasis and strikethrough limits
 
-Unlike standard Markdown, doxygen will not touch internal underscores or
-stars, so the following will appear as-is:
+Unlike standard Markdown and Github Flavored Markdown doxygen will not touch internal underscores or
+stars or tildes, so the following will appear as-is:
 
     a_nice_identifier
 
-Furthermore, a `*` or `_` only starts an emphasis if
+Furthermore, a `*` or `_` only starts an emphasis  and a `~` only starts a strikethrough if
 - it is followed by an alphanumerical character, and
 - it is preceded by a space, newline, or one the following characters `<{([,:;`
 
-An emphasis ends if
+An emphasis or a strikethrough ends if
 - it is not followed by an alphanumerical character, and
 - it is not preceded by a space, newline, or one the following characters `({[<=+-\@`
 
-Lastly, the span of the emphasis is limited to a single paragraph.
+Lastly, the span of the emphasis or strikethrough is limited to a single paragraph.
 
 
 \subsection mddox_code_spans Code Spans Limits
diff --git a/doc/output.doc b/doc/output.doc
index 3a24a60..6d1a567 100644
--- a/doc/output.doc
+++ b/doc/output.doc
@@ -32,7 +32,7 @@ The following output formats are \e directly supported by doxygen:
     Word. If you have success with other programs, please let me know.
 <dt><b>XML</b>
 <dd>Generated if \ref cfg_generate_xml "GENERATE_XML" is set to \c YES in the configuration file.<p>
-<dt><b>Docbook</b>
+<dt><b>DocBook</b>
 <dd>Generated if \ref cfg_generate_docbook "GENERATE_DOCBOOOK" is set to \c YES in the configuration file.<p>
 </dl>
 
diff --git a/doc/searching.doc b/doc/searching.doc
index cb6b84a..9bc518a 100644
--- a/doc/searching.doc
+++ b/doc/searching.doc
@@ -126,7 +126,7 @@ has its own advantages and disadvantages:
    options you may want to set. After doxygen has finished you will find
    a Makefile in the HTML output directory. Running "make install" on this
    Makefile will compile and install the doc set.
-   See <a href="https://developer.apple.com/library/mac/#featuredarticles/DoxygenXcode/_index.html">this 
+   See <a href="https://developer.apple.com/library/archive/featuredarticles/DoxygenXcode/_index.html">this 
    article</a> for more info.
 
    Advantage of this method is that it nicely integrates with the Xcode
@@ -139,7 +139,7 @@ has its own advantages and disadvantages:
 <h2>6. Qt Compressed Help</h2> 
    If you develop for or want to install the Qt application framework,
    you will get an application 
-   called <a href="http://qt-project.org/doc/qt-4.8/assistant-manual.html">Qt assistant</a>. 
+   called <a href="http://doc.qt.io/archives/qt-4.8/assistant-manual.html">Qt assistant</a>. 
    This is a help viewer for Qt Compressed Help files (<code>.qch</code>).
 
    To enable this feature set \ref cfg_generate_qhp "GENERATE_QHP" to \c YES.
diff --git a/doc/starting.doc b/doc/starting.doc
index 0765a3b..64d3be0 100644
--- a/doc/starting.doc
+++ b/doc/starting.doc
@@ -263,7 +263,7 @@ capabilities of the man page format, so some information
 \subsection docbook_out DocBook output
 \addindex docbook
 Doxygen can also generate output in the 
-<a href="http://docbook.org/">DocBook</a> format. How to process the
+<a href="https://docbook.org/">DocBook</a> format. How to process the
 DocBook output is beyond the scope of this manual.
 
 \section step3 Step 3: Documenting the sources
diff --git a/doc/trouble.doc b/doc/trouble.doc
index 6b05cd3..c490ae1 100644
--- a/doc/trouble.doc
+++ b/doc/trouble.doc
@@ -128,7 +128,7 @@ please use PATCH as a keyword in the bug entry form.
 
 If you have ideas how to fix existing bugs and limitations please discuss them on 
 the <a href="http://sourceforge.net/mail/?group_id=5971">developers mailing list</a> 
-(subscription required). Patches can also be sent directly to dimitri@stack.nl if 
+(subscription required). Patches can also be sent directly to doxygen@gmail.com if 
 you prefer not to send them via the bug tracker or mailing list.
 
 For patches please use
diff --git a/doc/xmlcmds.doc b/doc/xmlcmds.doc
index 848858d..b59095b 100644
--- a/doc/xmlcmds.doc
+++ b/doc/xmlcmds.doc
@@ -104,7 +104,7 @@ class Engine
 
 
 \htmlonly
-Go to the <a href="langhowto.html">next</a> section or return to the
+Go to the <a href="emojisup.html">next</a> section or return to the
  <a href="index.html">index</a>.
 \endhtmlonly