[Tagging] Turn Lane Tagging?

[Mike N]

I'm seeing a number of turn lane tagging fixes referencing 
http://osmlab.github.io/to-fix/#/admin/invalidturnlanes and making fixes 
such as

before:
    lanes=4
    oneway=yes
     turn:lanes =left|through|through;right

after:
    lanes=4
    oneway=yes
    left|||

  The wiki at http://wiki.openstreetmap.org/wiki/Key:turn:lanes doesn't 
seem to match.   Is this new, and where is it documented?

  Thanks,