At one point, Tk::TextUndo supported the four following features: <F5> indent selected text block <F6> unindent selected text block <F7> comment selected text block <F8> uncomment selected text block They were included as undocumented and unsupported features. The user could select a block of text, and by pressing <F5> every line selected would be prefixed with a tab at the start of the line. Somewhere along the line, these features stopped working. This tarball includes a recent version of Tk::TextUndo where the above features are working properly again.