There are also other special ones that can be used such as:

%c broadcasts your class.

%l broadcasts your current location (or nearest landmark).

%h broadcasts your current health level.

%t broadcasts the current time.

By mixing those in with messages, you can come up with some quite useful shortcuts:

bind “#” “say_team I'm a %c at %l with %h health remaining”

that would out put "I'm a Grenediar at the barrels with 50% health remaining"

There are other ones such as %i outputs the name of the person you are looking at and then you can have some fun.

bind "m" "say I am behind %i and I like what I see, nice bum!