The Data Compression/Expansion (DCX) facility routines decrease the size of text, binary data, images, and any other type of data. There is no DCL-level interface to this facility, nor is there a DCX utility.
DCX$ANALYZE_DATA DCX$ANALYZE_DONE DCX$ANALYZE_INIT DCX$COMPRESS_DATA DCX$COMPRESS_DONE DCX$COMPRESS_INIT DCX$EXPAND_DATA DCX$EXPAND_DONE DCX$EXPAND_INIT DCX$MAKE_MAP