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Divine Spirit, a Priest buff that (at the time) provided a flat +Spirit buff. Thanks to Mark B for providing proof.
Power Word: Fortitude, a Priest buff that increases Stamina. At the time, it was a flat +Stamina buff.
Arcane Intellect, a legacy Mage spell that was a shorter, reagent-free version of Arcane Brilliance. It granted a flat +Intellect buff, but was made obsolete when the reagent cost was removed from Arcane Brilliance.
Aspect of the Hawk, a legacy Hunter aura that increased Attack Power by a flat amount.
Resist Fire, a buff you got by using Mind Control on the Scarshield Spellbinder mobs in LBRS/UBRS. Many Raids used this for Molten Core and Blackwing Lair.
The red shield looks like something a Fire Resistance Potion of some sort would give you. I'm not sure what the first unknown one is, but I really feel like I should know it! (source: I played on a private vanilla server 2 years ago)
@Pyritie Most potion buffs used the icon of the potion themselves (or at least they did back then). I'm pretty sure the first one is a Paladin or Priest buff, I just can't put my finger on it at the moment. The rest is pretty much from memory, but classic was a looong time ago now and I stopped playing just prior to WoD.
I remember making a ton of those fire protection potions and that was definitely the icon they used. Vanilla wasn't very consistent with icons. Here's the buff they gave: wow-one.com/database/index.php?spell=17543
@Pyritie I seem to recall the elemental protection potions weren't actually resistance potions as such, they just gave a one or two minute shield that blocked the next X damage from that school