Basically, a condition-parameter that checks to see if a player is wearing "x" armour in "y" slot. The parameter could be called "armor:" with "armour:" as an alias. I don't know if this has been suggested as a ticket before, but if not, here is the ticket now.

The format could work like this:

armour: [(slot-name)@(item-type)@(modifier)(data-integer), (repeat), (repeatAgain), (etc.)]

An example:

armour: [HANDS@TARTARITE_SWORD@<60, HEAD@LEATHER_HELMET@4]

The player must be holding a "TARTARITE_SWORD" in their hand, and that sword must have at most 60 points of damage, or less. They must also be wearing any leather helmet with exactly 4 points of damage.

This parameter could also be used to check (as a side-effect) what item the player is currently holding, and what equipment mobs could have (even though you could have already done that, but this makes it easier to read).

I'm sure there are better ways to approach this parameter's format, but this is a start.