The P{lacZ} entry in FlyBase is used to denote the transgenic construct present in an insertion when it is known that the inserted element is a P-element based enhancer trap construct that encodes a lacZ reporter, but the precise transgenic construct that has been inserted is not known or is unspecified.
construct_comment: Identity uncertain: lacZ enhancer-trap construct, not specified which; probable candidates listed under "member of a series."