X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/3907e630a71d48e693062b350571990d7ba08bbb..bd358779861f265a7acff31ead40172735af693e:/doc/lispref/symbols.texi

diff --git a/doc/lispref/symbols.texi b/doc/lispref/symbols.texi
index 02cb83451c..82dfa0f491 100644
--- a/doc/lispref/symbols.texi
+++ b/doc/lispref/symbols.texi
@@ -1,6 +1,7 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990-1995, 1998-1999, 2001-2012 Free Software Foundation, Inc.
+@c Copyright (C) 1990-1995, 1998-1999, 2001-2013 Free Software
+@c Foundation, Inc.
 @c See the file elisp.texi for copying conditions.
 @node Symbols
 @chapter Symbols
@@ -538,8 +539,9 @@ deleted from the local value of a hook variable when changing major
 modes.  @xref{Setting Hooks}.
 
 @item pure
-This property is used internally to mark certain named functions for
-byte compiler optimization.  Do not set it.
+If the value is non-@code{nil}, the named function is considered to be
+side-effect free.  Calls with constant arguments can be evaluated at
+compile time.  This may shift run time errors to compile time.
 
 @item risky-local-variable
 If the value is non-@code{nil}, the named variable is considered risky