[Web-cyradm] request for clarification: $freenames, $freeaddress & "Mail transport"

[OpenMacNews]

hi all,

i've been plodding thru the code, and following a number of threads here re: 
the use/application of $freenames & $freeaddress in the code (e.g., 
newdomain.php).

is there a clear statement (perhaps even documentation?) as to what these do, 
and to which parameters (e.g. DOMAINS_AS_PREFIX, etc) they are 'sensitive'?

same for the "Mail Transport" pulldown in newdomain.php, where it states "Leave 
this as is, unless you know what you are doing".  Some 
explanation/documentation would be nice to have here ...

thx,

richard