The specification for "mv" is as specified in the SUS but with the following differences as listed below.
make backup before removal
override the usual backup suffix
remove any trailing slashes from each SOURCE argument
override the usual backup suffix
move all SOURCE arguments into DIRECTORY
move only older or brand new non-directories
explain what is being done
output version information and exit
The backup suffix is ~, unless set with --suffix or SIMPLE_BACKUP_SUFFIX. The version control method may be selected via the --backup option or through the VERSION_CONTROL environment variable. Here are the values:
never make backups (even if --backup is given)
make numbered backups
numbered if numbered backups exist, simple otherwise
always make simple backups