This paper deals with forward references (also called kataphoric references) in natural language. In order to calculate truth conditions for sentences that involve kataphoric references, an extension of Discourse Representation Theory, PATIENT DRT, is proposed, inspired by so-called backpatching techniques for the parsing of programming languages. The main idea is that a kataphoric element introduces an incomplete discourse entity, to be completed by subsequent material under certain conditions. This approach is applicable to pronominal as well as complex Noun Phrases, and has no special difficulties with crossing co-references. The main virtue of this approach is that it allows parsing of kataphors from left to right, which makes it suitable for on-line language processing by computer and plausible as an element of a theory of human language processing as well. However, the approach suggests that a left-to-right treatment of kataphoric constructions is hard to reconcile with the requirements of compositionality.