Hey August!

I wasn't referring to just the quote initials when commenting on distinguishing quotes from the rest of the MSG.  Instead to the entire quoting prefix whether or not there are initials, spaces, etc. within the prefix.  According to http://ftsc.org/docs/fsc-0032.001;

 > Newly quoted text should be preceeded by the a single space,
 > a greater than symbol ('>') and another space.

Other than tacking on the prefix ' > ' the above quote is an exact replica of the original text.  This differs slightly from what Nick last posted where the prefix omitted the leading space, '> '.  Either way works for me but am noting that mutt (email agent with vim as default editor) uses the '> ' quote prefix which appears to be the norm in traditional email applications.

As for the threading codes, I am assuming you are referring to MSGID/REPLY, which in the case of this REPLY, will work but will not work if a proper MSGID doesn't exist in the MSG one is REPLYing to.  Also quotes can exist in posts that aren't a REPLY.

Life is good,
Maurice

 o-  -o   -o   -o
/)    (\   (\   (\
^^    ^^   ^^   ^^
... šonne se heretoga wacaš šonne biš eall se here swiše gehindred.
    When the general weakens, the whole army is greatly hindered.
--- GNU bash, version 5.2.37(1)-release (x86_64-pc-linux-gnu)