- Health care enterprises need enterprise-wide terminologies to compare, reuse and repurpose health care descriptions. But once they are created, these terminologies need to be maintained and enhanced to sustain their utility and that of the descriptions encoded with them. MEME II (Metathesaurus Enhancement and Maintenance Environment, Version II) supports the required activities and enables enterprises to leverage their investment in terminology and descriptions by permitting remote-extra-enterprise-enhancements to terminology to be incorporated locally, and local-intra-enterprise-enhancements to be shared remotely. MEME II represents all changes to terminologies as data, or "actions," that can be interpreted by an "action engine." These actions, or messages, represent semantic "units of work" that can be interpreted by other copies of MEME II. The exchange of update messages increases the likelihood that the comparability of terminology-based health care descriptions can be sustained.