NB: More recent documentation for Dyalog APL is available at https://docs.dyalog.com/20.0/.

UCMDCacheFile

This parameter specifies the name of the User Command cache file.

The default value is:

UserCommand{UcmdMajor}{UcmdMinor}.{DyalogMajor}{DyalogMinor}{U|C}{bits}.cache

For example, UserCommand25.182U64.cache