Thanks for your really helpful report and pointers.
In thumbing through a Web book I came across a reference to an html
entity reference for a macron (¯) next door to entity
references that I'm familiar with, and it seemed to have a code number
of #175 or something like that.
So at some level it exists, but when I tried to do use it on Netscape or
Oracle Browser it didn't work.
I don't know much about the semantics of this, but in a general way,
overbars have been the most widely used symbols to denote long vowels:
you run into them in books all the time, and they have the advantage of
not being tied to a particular language. So I'd probably use it if it
worked. but it doesn't.
Professor of English and Classics
Department of English
Evanston IL 60208
847-864-3496 (home and voice mail)