BIP 329 Merged: Standard for Wallet Label Exports and Imports Between Wallets
BIP 329 sets a new standard that will make it easy for wallets to allow users to back up various types of wallet labels and import them into other compatible wallets.
The export and import of funds across different Bitcoin wallet applications is well defined through standards such as BIP39, BIP32, BIP44 etc. These standards are well supported and allow users to move easily between different wallets. There is, however, no defined standard to transfer any labels the user may have applied to the transactions, addresses, public keys, inputs, outputs or xpubs in their wallet. The UTXO model that Bitcoin uses makes these labels particularly valuable as they may indicate the source of funds, whether received externally or as a result of change from a prior transaction. In both cases, care must be taken when spending to avoid undesirable leaks of private information. Labels provide valuable guidance in this regard, and have even become mandatory when spending in several Bitcoin wallets. Allowing users to import and export their labels in a standardized way ensures that they do not experience lock-in to a particular wallet application.
It will be up to individual wallet maintainers to implement support for the new standard.
Developer Craig Raw of Sparrow Wallet proposed the standard.