OptionalartifactOptionalclearpartition ids to wipe, or CLEAR_ALL
Optionalinvalidatetag to the vector version at which it last changed
OptionalpartitionOptionalprotocolOptionalseenecho of the request's Spool-Vector-Seen: invalidate is the complete diff since this cursor
Optionalvector
every spool header of a response, decoded; an absent header is an absent field