* doc/Tcl.n (Variable substitution): [Bug 3099086]: Increase clarity

	of explanation of what characters are actually permitted in variable
	substitutions. Note that this does not constitute a change of
	behavior; it is just an improvement of explanation.

1 files changed, 9 insertions, 1 deletions

diff --git a/doc/Tcl.n b/doc/Tcl.n
index fd31dfc..eaa221d 100644
--- a/doc/Tcl.n
+++ b/doc/Tcl.n
@@ -5,7 +5,7 @@
 '\" See the file "license.terms" for information on usage and redistribution
 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 '\" 
-'\" RCS: @(#) $Id: Tcl.n,v 1.24 2010/01/13 12:08:30 dkf Exp $
+'\" RCS: @(#) $Id: Tcl.n,v 1.25 2010/11/04 13:51:41 dkf Exp $
 '\"
 .so man.macros
 .TH Tcl n "8.5" Tcl "Tcl Built-In Commands"
@@ -110,6 +110,8 @@ Variable substitution may take any of the following forms:
 \fIName\fR is the name of a scalar variable;  the name is a sequence
 of one or more characters that are a letter, digit, underscore,
 or namespace separators (two or more colons).
+Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
+\fBA\fR\-\fBZ\fR and \fBa\fR\-\fBz\fR).
 .TP 15
 \fB$\fIname\fB(\fIindex\fB)\fR
 .
@@ -117,6 +119,8 @@ or namespace separators (two or more colons).
 the name of an element within that array.
 \fIName\fR must contain only letters, digits, underscores, and
 namespace separators, and may be an empty string.
+Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
+\fBA\fR\-\fBZ\fR and \fBa\fR\-\fBz\fR).
 Command substitutions, variable substitutions, and backslash
 substitutions are performed on the characters of \fIindex\fR.
 .TP 15
@@ -136,6 +140,10 @@ substitutions are performed during the parsing of \fIname\fR.
 .PP
 There may be any number of variable substitutions in a single word.
 Variable substitution is not performed on words enclosed in braces.
+.PP
+Note that variables may contain character sequences other than those listed
+above, but in that case other mechanisms must be used to access them (e.g.,
+via the \fBset\fR command's single-argument form).
 .RE
 .IP "[9] \fBBackslash substitution.\fR"
 If a backslash