HOW Can I List Package options ?

Hi all,
I'm trying to understand how can i enable or disable features when I 
"port install" a package.
For example if I port Squid (web proxy server) it is built with 
error-messages_in_english.
If I manually download when i run ./configure command I can add 
--with_default_error_language=Italian
or for example I can add icmp support ... and so on.

Now the question is how can I ask port command to list all features 
included with a package?


Is there olso a way to pass to the compiler (gcc) a particular option 
(for ex -fast or -O2) ... in the ./configure way i do this whith 
CFLAGS .

sorry ... but i'm a new user of DarwinPort

thanks a million to anyone can help me.

-- 
Filippo