added backwards compatibility and copyright

Author: DanielWeigl

bip-p2sh-accounts.mediawiki

@@ -62,6 +62,10 @@ To derive the P2SH address from the above calculated public key, we use the enca
     scriptPubKey: HASH160 <20-byte-script-hash> EQUAL
                   (0xA914{20-byte-script-hash}87)
 
+==Backwards Compatibility==
+
+This BIP is not backwards compatible by design as described under [#considerations]. A not compatible wallet will not discover accounts at all and the user will notice that something is wrong.
+
 
 ==Test vectors==
 
@@ -94,3 +98,7 @@ To derive the P2SH address from the above calculated public key, we use the enca
 * [[bip-0043.mediawiki|BIP43 - Purpose Field for Deterministic Wallets]]
 * [[bip-0044.mediawiki|BIP44 - Multi-Account Hierarchy for Deterministic Wallets]]
 * [[bip-0141.mediawiki|BIP141 - Segregated Witness (Consensus layer)]]
+
+== Copyright ==
+
+This document is placed in the public domain.