In this paper, we describe a practice that is common across multiple heterogeneous contexts but enacted differently depending on the unique constellation of resources and demands present in each local context. Using the case of informal documentation practices in two departments of a single hospital, Emergency and Labor & Delivery, we describe how clinicians in each department develop contextualized informal documentation practices after deployment of a new EMR system. We describe three underlying functions of informal documentation that are inherent to the practice of medical personnel: "memory work," abstraction work," and "future work." We then find that the newly deployed EMR technology does not support these kinds of work. We argue that hospital documentation work systems should be designed with an eye to such universal work practices, while keeping in mind that the effectiveness of informal documentation practices is rooted in its adaptive and flexible deployment in heterogeneous work settings.