OptionalavatarThe grantee — user:{uid} | group:{gid}. This is the canonical name (core_concepts §4: "principal" is reserved for the authority context; a space member is a grantee). The host populates this on every member row.
OptionalloginUse Member.grantee. Kept as an alias (same value) for back-compat during the principal→grantee migration; will be removed in a future major. The host still populates both.
A member of a space (for the share/manage UI).