The nominal after bă is typically an affected undergoer. For instance, in the sentence 他把一本書撕成兩半 (tā bǎ yī běn shū sī chéng liǎng bàn/ He tore a book into two pieces.), the nominal 一本書 is affected, resulting from its being torn into two pieces.
Secondly, the nominal after b˘a (把) must be semantically specific, generic, or definite.
Furthermore, the predicate of the event must indicate a change of state. Verbs without an end of the event is not allowed. For instance, *他把一本書賣了 is ungrammatical, as it’s impossible to indicate a change of state involving an entity not existing in a given discourse. In short, referential constraint signifies that the referent of the nominal marked by bă (把) must exist in the discourse.
Reference: Chinese: a linguistic introduction by Chao Fen Sun