There is only one file type that uses the .UWL extension:
User Word List File
File used by spell checker programs in Corel WordPerfect and Novell GroupWise word processor programs; contains a list of user-added words that are recognized and validated by the spell checker in document text.
UWL files are saved in the format "WTXXYY.UWL", where "XX" is the program version and "YY" is the code for language or location of origin (e.g., "US" for US English).
Older UWL files may be imported into newer versions of WordPerfect by renaming the version digits in the UWL file. In some program versions, you may also update older files to newer program formats using the User Word List option in the spell checker.
Updated: December 16, 2009