Is there a way to make the item at the top of a unit's inventory unable to be traded?

Questions
1

Topic^

The reason I want this is so that a player can’t use Trade to equip a unit with another weapon.

2

Assuming it’s a regular menu command, you could swap out the effect routine with one that does nothing.

3

what is it with you and bad ideas?

either way I’m sure something that simple is doable, it’s only a matter of if it’s been done before.