The documentation for the [[rename]] command is available at http://purl.org/tcl/home/man/tcl8.5/TclCmd/rename.htm . The [[rename]] command is most often used for [wrapping commands]. In other words, the programmer uses [[rename]] to hide another command -- so that a wrapper can be placed around the hidden command to change its behavior. Examples of this important concept abound on the Wiki; among the clearest are: [DGP]: Be aware that if you `rename` a command into another * [Overloading widgets] * [Text variable for text widget] * [Forward compatibility] [[Discuss examples. Explain errorInfo subtleties (refer to live examples). Explain "return [[eval ::_$original_command \$first_argument $args]]" idiom.]] [RS] Another frequent application for [rename] is to remove commands, by renaming them to the empty string: rename foo {} [DGP] Be aware that if you [[rename]] a command into another namespace, its evaluation context will change to that namespace. [HaO] 2010-04-10: ([http://groups.google.com/group/comp.lang.tcl/browse_thread/thread/20a6f0cb2e9912a9#%|%discussion on CLT%|%]): rename or delete from inside targeted proc is allowed: % namespace eval one { variable message "I'm in one" proc test {} {variable message; return $message} } % namespace eval two {variable message "I'm in two"} % rename one::test two::test % two::test I'm in two ---- [Tcl syntax help] - [Arts and crafts of Tcl-Tk programming] - [Category Command]