[c-nsp] what is the meaning of WS-X6816?!!

[mohamed Osama Saad Abo sree]

Dear all,

I know this is a strange question,I know this is a gigabit ethernet
switching module,But i want to know the meaning of the extension and how
cisco decide them.

you can find WS-X64,WS-x67,WS-X68.....also Perl...so i want to know how
different modules are organized and categorized without searching Google or
Cisco :) to build something like Mental Database for Line cards and
modules,so you can decide what you need as fast as possible.

Kindest Regards,
Osama