signal(3) "new" signals warning

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

Out signal(3) man page screams at the reader with emphasis:

   Unlike previous signal facilities, the handler func() remains
   installed after a signal has been delivered.

This paragraph and its supposed importance is probably a bit opaque
for a modern reader.  It has not been relevant in ... 35-40 years?  It
refers to the historic behavior (v7, 4BSD), where signal disposition
was reset to SIG_DFL after a signal was handled.

I think it's time we reword this and move it to HISTORY, but my memory
is hazy.  It seems 4.1BSD was transitional, and 4.2BSD had new signals
as the default and introduced the above phrase in signal(3).
Feedback, clarifications and proposed new wording are appreciated.

-uwe