usermod's man refers to --*-sub-uids but accepts only --*-subuids

The man page refers to sub-uids and sub-gids but those don't take any "-" between sub and [ug]ids. The help message conforms to what the command accepts though.

$ man usermod | grep -F -- -sub
       -v, --add-sub-uids FIRST-LAST
       -V, --del-sub-uids FIRST-LAST
           This option may be specified multiple times to remove multiple ranges to a users account. When both --del-sub-uids and --add-sub-uids are specified remove of all subordinate uid ranges happens before any
       -w, --add-sub-gids FIRST-LAST
       -W, --del-sub-gids FIRST-LAST
           This option may be specified multiple times to remove multiple ranges to a users account. When both --del-sub-gids and --add-sub-gids are specified remove of all subordinate gid ranges happens before any

$ usermod --help | grep -F -- -sub
  -v, --add-subuids FIRST-LAST add range of subordinate uids
  -V, --del-subuids FIRST-LAST remvoe range of subordinate uids
  -w, --add-subgids FIRST-LAST add range of subordinate gids
  -W, --del-subgids FIRST-LAST remvoe range of subordinate gids

More info on the environment:

$ lsb_release -rd
Description: Ubuntu 14.04.2 LTS
Release: 14.04

$ apt-cache policy passwd
passwd:
  Installed: 1:4.1.5.1-1ubuntu9
  Candidate: 1:4.1.5.1-1ubuntu9
  Version table:
 *** 1:4.1.5.1-1ubuntu9 0
        500 http://archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: passwd 1:4.1.5.1-1ubuntu9
ProcVersionSignature: Ubuntu 3.13.0-46.77-generic 3.13.11-ckt15
Uname: Linux 3.13.0-46-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Mar 3 13:37:50 2015
InstallationDate: Installed on 2014-01-26 (400 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140124)
SourcePackage: shadow
UpgradeStatus: No upgrade log present (probably fresh install)