What of those readers that truncate long lines or as in your app's case
oddly truncate subject lines that have mulitple "OT:" in them? I'd think
that the multiple tree roots would be the more desirable consequence.

Those wouldn't be issues either.

Truncating: Avoiding the colon doesn't lengthen the line (except for the
first re. It merely keeps the original OT in the subject line. It
ensures that "OT" is not treated special.

My app doesn't "oddly trucnate subject lines". Other apps do when they
reply. Then =everybody's= app (including mine) gets multple subject
lines, defeating the point of a prepend. Check out prior threads which
started with OT and a colon, or watch the "OT: Eagle, not waddling"
thread develop and you'll see a new subject line appear without the OT
as soon as somebody replies to it with a "bad" reader.

I don't understand when multple tree roots would be better.

Jose
--
There are two kinds of people in the world. Those that just want to
know what button to push, and those that want to know what happens when
they push the button.
for Email, make the obvious change in the address.