> curly brackets are syntactically significant in strings - and comments.

The latter trips me up far more than I would like to admit :(

It's a great example of the nature of Tcl as a language, though. Sometimes I love the simplicity, sometimes consequences of it drive me nuts.

For those who haven't used Tcl: You write comments like this:

    # this is a comment

But, in keeping with Tcl's simple and tiny nature, this isn't a special case. "#" is simply a procedure that ignores all arguments supplied to it!

While this is extremely elegant, and means you could implement comments in Tcl itself rather than the interpreter, it does mean that you have to balance your curly brackets within comments, which is hugely annoying when you forget.