Prefix on every IdentityMapEntry.reason minted from an ACCEPTED
successor claim: successor:footprint or successor:position. Distinct
from CONTENT_MATCH_REASON_PREFIX so a filter can tell an
engine-committed pairing from a heuristic one a human accepted.
Prefix on every IdentityMapEntry.reason minted from an ACCEPTED successor claim:
successor:footprintorsuccessor:position. Distinct from CONTENT_MATCH_REASON_PREFIX so a filter can tell an engine-committed pairing from a heuristic one a human accepted.