I have already read much about LaTeX3 on TeX.SE, in TeX Live’s documentation and in TUGBoat, but there is something I do not yet understand: is the expl3 syntax meant to be used in document-level commands?
I would be truly delighted if it was possible to include the caracthers :
and _
in command names defined with \newcommand
or an equivalent LaTeX3 definition construct. That would bring “namespaces in the document”, so to speak, and generally make commands more readable (in my opinion). Since I always have to work with XML and HTML in my professional life, I would like to make my LaTeX markup more similar to XML’s elements and attributes, at least superficially.
Going further down this line of thinking, a side question is: is it somehow possible to use non-ASCII letters in LaTeX3 command names?
P.S.: Yes, I do pursue the foolish dream of semantic markup in LaTeX :-).