...
>> > E.g. do you know what the lead in characters for an ANNA annotation are?
>>...
>>
>> They were:  --|
>
>I believe this is based on an IEEE spec.  Anyone familiar with it?

The Anna convention is NOT based on the IEEE "Ada as a PDL" recommended
practice (misrepresented as a "standard" after its publication in the
mid/late 80's).  The original Anna work (about 1980-81) preceded even the
1982 start of that IEEE working group, and defined the "--|" mark then.
--hh