The mailing list for listmasters using Sympa

[address@concealed]

another question,

when i was reading in the FAQ i found How to reject, detach or control 
attachement in a mailling list question.

In the answer it was written the following 
"you may create a new send.xx scénario (create ~sympa/etc/scenari/send.xx) 
and apply xx for the send parameter of the related list"

can anyone calrify more what is xx stands for ?
and what is the send parameterof the related list ?

Thanks in advance,
Kamel