Items usable for certain hero types

What is the best way to make a custom item only useable by a certain hero type?

What do you mean 'hero types' you mean race? melee/ranged? male female? Just set all the heros of one type to one variable and all of another type to another variable. Then just check if the item correlates with the hero type when he/she picks it up/targets it.

"Then just check if the item correlates with the hero type when he/she picks it up/targets it."

That is the tricky part. What can I do to the item once this occurs? Currently I can only drop the item if the hero acquires it. Maybe this is for the best anyways. Originally I was wanting to make the shops not sell the item to the hero type and if the hero picked the item up it would be unusable.