Battle Armor Record sheets, what's the S stand for?

[MoneyLovinOgre4Hire]

I've noticed that some weapons on Battle Armor record sheets have an S in brackets next to them.  In a game today, one player stated that this designated that a given weapon was a Squad Support Weapon (specifically, the Light Recoilless Rifle on the Marauder BA), but the TRO entry for the Marauder BA makes no mention of it having Squadron Support Weapons of any kind.  So what does the S stand for?

[nckestrel]

Trick question.
There should not be an S there. It should be AI.
(Assuming you are looking at Technical Readout 3145 Mercenaries, and the S on the light recoilless rifle. Record Sheets Technical Readout 3145 shows the Marauder BA's light recoilless rifle correctly with DB, AI.)
S is for switchable ammo.  But the light recoilless rifle does not have switchable ammo.

The weapon codes are on pages 113-114 of Total Warfare or pages 96-97 of the BattleMech Manual.

[MoneyLovinOgre4Hire]

Great, thanks.  And yes, I was looking at the record sheet from TRO 3145 Mercenaries.