# Breaking Changes This is a history of NIP changes that potentially break pre-existing implementations, in reverse chronological order. | Date | Commit | NIP | Change | | ----------- | --------- | -------- | ------ | | 2024-02-16 | [cbec02ab](https://github.com/nostr-protocol/nips/commit/cbec02ab) | [NIP-49](49.md) | Password first normalized to NFKC | | 2024-02-15 | [afbb8dd0](https://github.com/nostr-protocol/nips/commit/afbb8dd0) | [NIP-39](39.md) | PGP identity was removed | | 2024-02-07 | [d3dad114](https://github.com/nostr-protocol/nips/commit/d3dad114) | [NIP-46](46.md) | Connection token format was changed | | 2024-01-30 | [1a2b21b6](https://github.com/nostr-protocol/nips/commit/1a2b21b6) | [NIP-59](59.md) | 'p' tag became optional | | 2023-01-27 | [c2f34817](https://github.com/nostr-protocol/nips/commit/c2f34817) | [NIP-47](47.md) | optional expiration tag should be honored | | 2024-01-10 | [3d8652ea](https://github.com/nostr-protocol/nips/commit/3d8652ea) | [NIP-02](02.md) | list entries should be chronological | | 2024-01-10 | [3d8652ea](https://github.com/nostr-protocol/nips/commit/3d8652ea) | [NIP-51](51.md) | list entries should be chronological | Breaking changes prior to 2024-01-01 are not yet documented. ## NOTES - If it isn't clear that a change is breaking or not, we list it. - The date is the date it was merged, not necessarily the date of the commit.