Standard Equipment refers to the weapons/gear/objects that a character usually carries with them, and thus would be expected to have by default in an OBD fight. It does not include such things as special one-time powerups, weapons the character carried only for a short period, or things that the character wouldn't normally have with them and would need prep to build/acquire.
For example, Batman from DC Comics would carry such things as batarangs, a grappling hook, smoke bombs, lockpicks, flashbangs, etc. as standard equipment, but things like the Batmobile, his shard of Kryptonite, JLA Watchtower and New Gods tech, etc. would not be standard equipment, even though he could easily acquire those things with prep.