Currently listunspent only exposes a safe which is coded roughly as confirmations > 0 || (is_mine && !replaceable) however a consumer very well might want to distinguish between when it's "mine" and when it's not (as I presently need to).
This ideally would be extended to listunspent, gettransaction and listtransactions.
(The listtransactions already exposes a "trusted" which is basically "is_mine" but also uses the spendZeroConf configuration, which is imho rather confusing. So my suggestion would be that all apis expose a consistent set of "is_mine", "replaceable" and "confirmations" (which is already always exposed) and RPC consumers can use these primitives to make decisions.