The 32-bit Command Interpreter uses three message files for the text of its informational and error messages. These files are located whenever a message is required by searching the directories listed in the DPATH environment variable.
It expects the OSO001.MSG file, supplied as standard with the
operating system, to contain the text of various operating system
messages.
It, and various external commands, also obtain various error messages from
the CMD.MSG file, and on-line help text (as obtained by
the standard /? option to all commands)
from the CMDH.MSG file.