Mailer questions

I have a few questions about the Cypherpunk remailers that
hopefully someone can answer for me:

What is the maximum length of a "Request-Remailing-To:" header?  
Can several of them be inserted for lengthy lists?  Regarding the 
"mail-to-Usenet" posting gateways, where you typically replace 
the dots in newsgroup names with hyphens, what about groups that 
have hyphens in their names?  Can the posting software tell the 
hyphens apart?

I understand that several of the headers can be changed by using 
a "##" token instead of "::".  Which ones can be changed and 
which ones can't?

Has anyone had any experience chaining from a Cypherpunk-style 
remailer to anon.penet.fi?  Can a "::" separator be used 
successfully, or which format will work?

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