add discussion of link to SIGHASH_GROUP and covenants

bip-ephemeralanchors.mediawiki

@@ -85,6 +85,8 @@ perhaps reduced in severity or chance of success.
 
 ===Related Work===
 
+[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2023-January/021334.html SIGHASH_GROUP] style proposals are an alternative method of bringing funds to a transaction without involving CPFP by enacting a softfork. Making these pin-resistant may require follow-on policy work, or [https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-May/020458.html more general covenants] to directly stop pins we want to avoid. The drawbacks of these are the necessity of a softfork and all that entails.
+
 [https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2020-September/018168.html Transaction Sponsors] is a softfork proposal to allow transactions to
 indirectly sponsor transactions with no explicit relationship in the classical utxo
 model. Ephemeral Anchors can be viewed as a type of opt-in transaction sponsors implemented