Comment #4 on issue 3119 by [email protected]: Repeat barlines and rests http://code.google.com/p/lilypond/issues/detail?id=3119
The changes in the bar line interface were due to a kind of WYSIWYG approach: the thick bar line is represented by a '.', the thin bar line by a '|' and the repeat dots by ':'. If we allow for aliases as you proposed the whole interface would get cluttered up.
