Quote Originally Posted by xXHoax View Post
*"Он - любящ." For instance, is incorrect. Because the active participles don't ever get used in this way, there exist no short forms from them.
Even this is not entirely true. For example. you can say:

Он в этих делах сведущ.

That word is clearly derived from an active participle, although it's switched to being classified as an adjective now.