OK. Kinda like cowami says, there's only a single tier of unlocks in Special Forces but there's a little more that makes it confusing.
In SF you have the L85A1 available as the unluck if you're a medic, right? So if you're on Warlord for example and you're on the Insurgent team you can pick that over the AK-10 if you want to. Same if you're SAS, only the default weapon is different... check what you're carrying if you spawn with the default weapon as an SAS medic. Or if you're in a hurry look here:
http://wiki.bf2s.com/armies/battlefield … forces/sasNow for AT, in SF the unlock available is the DAO but none of the sides have the P90, it isn't in Special Forces (same with the L96A1) you just get them unlocked for use in normal BF2 if you have SF or have played it once. Doesn't really make sense but there you go, the game's history is a little muddled.