This is the Matching Extension Ranking List (MERL) schema as first introduced by the publication "dbling: Identifying Extensions Installed on Encrypted Web Thin Clients". As described more fully in the paper, the purposes of a MERL file are to:

1. List (using their inode numbers) evidence artifacts that have been evaluated to be potential root directories for installed extensions, and
2. List the extensions calculated to be the most likely matches for each of these artifacts.

Because they serve a similar purpose, this schema directly references and depends on the DFXML schema.