Template:InheritVersionConstraints

• version: optional, two or three part version numbers, e.g. 1.0 up to 99.99, or 1.0.1 up to 99.99.99
  There may be an additional SVN release number (external link) for testing unofficial releases, e.g. 1.1r4 or 2.0r271, where the number after 'r' points to the release number in the Template:Sitel.
  If no SVN release number is used, the officially released railML version (link to the railML^® website) is bounded.
  For more information, see the wiki documentation about "Officially released versus developer version (Homepage, Subversion)"