The default search path is /bin:/usr/bin:/usr/ucb. To change the path, include anywhere in the file a line of the form:
PATH=/bin:/usr/bin:/usr/ucb
Normally, an acknowledgment is mailed back to the requesting site after the command completes. If a command name is suffixed with ,Error, then an acknowledgment will be mailed only if the command fails. If the command is suffixed with ,No, then no acknowledgment will ever be sent. (These correspond with the -z and -n options of uux, respectively.)
For most sites, L.cmds should only include the lines:
rmail
ruusend
News sites should add:
PATH=/bin:/usr/bin:/usr/ucb:/usr/new
rnews,Error
While file names supplied as arguments to uux commands will be checked against the list of accessible directory trees in USERFILE(5), this check can be easily circumvented and should not be depended upon. In other words, it is unwise to include any commands in L.cmds that accept local file names. In particular, sh(1) and csh(1) are extreme risks.
It is common (but hazardous) to include uucp(1C) in L.cmds; see the NOTES section of USERFILE.
/etc/uucp/L.cmds /etc/uucp/UUAIDS/L.cmds L.cmds example.