Archives/ARCHIVEID/cfg/static/
EPrints 3 Reference: Directory Structure - Metadata Fields - Repository Configuration - XML Config Files - XML Export Format - EPrints data structure - Core API - Data Objects
This directory represents the language-neutral top level of your website. Langauge specific files are in eprints3/archives/ARCHIVEID/cfg/lang/en/static/ (well, English ones are).
Files in this directory override files in eprints3/lib/static/.