As of now, it is not possible to include a close-bracket character in a bracketed set of allowed characters.
[scan]'s format uses bracketed sets of allowed characters, too, and it *does* allow a close-bracket as first char.
Having looked into the implementation of tcl's string-globbing, it seems that *before* entering that loop over the
bracketed characters, an initial check for ']' in the pattern and in the string to be matched would be a really simple
fix. Doing it that way, would even still allow a dash to be included verbatim, as well, by placing it right after the