Historical Rules · 1 April 2011
Rule 206.2c
Official source text from the 1 April 2011 Rules release
An ability word appears in italics at the beginning of some abilities on cards. Ability words are similar to keywords in that they tie together cards that have similar functionality, but they have no special rules meaning and no individual entries in the Comprehensive Rules. The ability words are channel, chroma, domain, grandeur, hellbent, imprint, kinship, landfall, metalcraft, radiance, sweep, and threshold.