In Discovering Timber-Framed Buildings the simple term collar is used with out the mention of tie or beam, just collar. If this member needs a color tie for the party it should be grey.

Hammer beam truss work uses the term collar. If the buttress or skimpy post fail the collar changes to a tension member?

Jim, if the tie beam on a king rod truss has a post or two under it is the king now a post? Tim