Merge branch 'ERC721Lockable' of https://github.com/streamnft-tech/EIPs…

… into ERC721Lockable

EIPS/eip-1.md

@@ -290,6 +290,42 @@ Permitted WHATWG specification URLs must anchor to a specification defined in th
 
 Although not recommended by WHATWG, EIPs must anchor to a particular commit so that future readers can refer to the exact version of the living standard that existed at the time the EIP was finalized. This gives readers sufficient information to maintain compatibility, if they so choose, with the version referenced by the EIP and the current living standard.
 
+### Internet Engineering Task Force (IETF)
+
+Links to an IETF Request For Comment (RFC) specification may be included using normal markdown syntax, such as:
+
+```markdown
+[RFC 8446](https://www.rfc-editor.org/rfc/rfc8446)
+```
+
+Which renders as:
+
+[RFC 8446](https://www.rfc-editor.org/rfc/rfc8446)
+
+Permitted IETF specification URLs MUST anchor to a specification with an assigned RFC number (meaning cannot reference internet drafts), and so MUST match this regular expression:
+
+```regex
+^https:\/\/www.rfc-editor.org\/rfc\/.*$
+```
+
+### Bitcoin Improvement Proposal
+
+Links to Bitcoin Improvement Proposals may be included using normal markdown syntax, such as:
+
+```markdown
+[BIP 38](https://github.com/bitcoin/bips/blob/3db736243cd01389a4dfd98738204df1856dc5b9/bip-0038.mediawiki)
+```
+
+Which renders to:
+
+[BIP 38](https://github.com/bitcoin/bips/blob/3db736243cd01389a4dfd98738204df1856dc5b9/bip-0038.mediawiki)
+
+Permitted Bitcoin Improvement Proposal URLs must anchor to a specific commit, and so must match this regular expression:
+
+```regex
+^(https://github.com/bitcoin/bips/blob/[0-9a-f]{40}/bip-[0-9]+\.mediawiki)$
+```
+
 ### Digital Object Identifier System
 
 Links qualified with a Digital Object Identifier (DOI) may be included using the following syntax:

EIPS/eip-6093.md

@@ -32,9 +32,9 @@ The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "S
 
 The following errors were designed according to the criteria described in [Rationale](#rationale).
 
-This EIP defines standard errors that may be used by implementations in certain scenarios, but does not specify whether implementations should revert in those scenarios, which remains up to the implementers, unless a revert is mandated by the corresponding EIPs.
+This EIP defines standard errors that may be used by implementations in certain scenarios but it does not specify whether implementations should revert in those scenarios, which remains up to the implementers unless a revert is mandated by the corresponding EIPs.
 
-The names of the error arguments are defined in the [Parameter Glossary](#parameter-glossary), and MUST be used according to those definitions.
+The names of the error arguments are defined in the [Parameter Glossary](#parameter-glossary) and MUST be used according to those definitions.
 
 ### [ERC-20](./eip-20.md)
 
@@ -43,15 +43,18 @@ The names of the error arguments are defined in the [Parameter Glossary](#parame
 Indicates an error related to the current `balance` of a `sender`.
 Used in transfers.
 
-- MUST be used when `balance` is less than `needed`.
-- MUST NOT be used if `balance` is greater than or equal to `needed`.
+Usage guidelines:
+
+- `balance` MUST be less than `needed`.
 
 #### `ERC20InvalidSender(address sender)`
 
 Indicates a failure with the token `sender`.
 Used in transfers.
 
-- MUST be used for disallowed transfers from the zero address.
+Usage guidelines:
+
+- RECOMMENDED for disallowed transfers from the zero address.
 - MUST NOT be used for approval operations.
 - MUST NOT be used for balance or allowance requirements.
   - Use `ERC20InsufficientBalance` or `ERC20InsufficientAllowance` instead.
@@ -61,67 +64,82 @@ Used in transfers.
 Indicates a failure with the token `receiver`.
 Used in transfers.
 
-- MUST be used for disallowed transfers to the zero address.
-- MUST be used for disallowed transfers to non-compatible addresses (eg. contract addresses).
+Usage guidelines:
+
+- RECOMMENDED for disallowed transfers to the zero address.
+- RECOMMENDED for disallowed transfers to non-compatible addresses (eg. contract addresses).
 - MUST NOT be used for approval operations.
 
 #### `ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed)`
 
 Indicates a failure with the `spender`'s `allowance`.
 Used in transfers.
 
-- MUST be used when `allowance` is less than `needed`.
-- MUST NOT be used if `allowance` is greater than or equal to `needed`.
+Usage guidelines:
+
+- `allowance` MUST be less than `needed`.
 
 #### `ERC20InvalidApprover(address approver)`
 
 Indicates a failure with the `approver` of a token to be approved.
 Used in approvals.
 
-- MUST be used for disallowed approvals from the zero address.
+Usage guidelines:
+
+- RECOMMENDED for disallowed approvals from the zero address.
 - MUST NOT be used for transfer operations.
 
 #### `ERC20InvalidSpender(address spender)`
 
 Indicates a failure with the `spender` to be approved.
 Used in approvals.
 
-- MUST be used for disallowed approvals to the zero address.
-- MUST be used for disallowed approvals to the owner itself.
+Usage guidelines:
+
+- RECOMMENDED for disallowed approvals to the zero address.
+- RECOMMENDED for disallowed approvals to the owner itself.
 - MUST NOT be used for transfer operations.
   - Use `ERC20InsufficientAllowance` instead.
 
 ### [ERC-721](./eip-721.md)
 
-### `ERC721InvalidOwner(address owner)`
+#### `ERC721InvalidOwner(address owner)`
 
 Indicates that an address can't be an owner.
 Used in balance queries.
 
-- MUST be used for addresses whose ownership is disallowed (eg. ERC-721 explicitly disallows `address(0)` to be an owner).
-- MUST not be used for transfers.
+Usage guidelines:
+
+- RECOMMENDED for addresses whose ownership is disallowed (eg. ERC-721 explicitly disallows `address(0)` to be an owner).
+- MUST NOT be used for transfers.
   - Use `ERC721IncorrectOwner` instead.
 
-### `ERC721NonexistentToken(uint256 tokenId)`
+#### `ERC721NonexistentToken(uint256 tokenId)`
 
 Indicates a `tokenId` whose `owner` is the zero address.
 
-- MUST be used when attempting to interact with a non-minted or burned token.
+Usage guidelines:
+
+- The `tokenId` MUST BE a non-minted or burned token.
 
 #### `ERC721IncorrectOwner(address sender, uint256 tokenId, address owner)`
 
 Indicates an error related to the ownership over a particular token.
 Used in transfers.
 
-- MUST be used when `sender` is not `owner`.
+Usage guidelines:
+
+- `sender` MUST NOT be `owner`.
 - MUST NOT be used for approval operations.
 
 #### `ERC721InvalidSender(address sender)`
 
 Indicates a failure with the token `sender`.
 Used in transfers.
 
-- MUST be used for disallowed transfers from the zero address.
+Usage guidelines:
+
+- RECOMMENDED for disallowed transfers from the zero address.
 - MUST NOT be used for approval operations.
 - MUST NOT be used for ownership or approval requirements.
   - Use `ERC721IncorrectOwner` or `ERC721InsufficientApproval` instead.
@@ -131,33 +149,41 @@ Used in transfers.
 Indicates a failure with the token `receiver`.
 Used in transfers.
 
-- MUST be used for disallowed transfers to the zero address.
-- MUST be used for disallowed transfers to non-`ERC721TokenReceiver` contracts or those that reject a transfer. (eg. returning an invalid response in `onERC721Received`).
+Usage guidelines:
+
+- RECOMMENDED for disallowed transfers to the zero address.
+- RECOMMENDED for disallowed transfers to non-`ERC721TokenReceiver` contracts or those that reject a transfer. (eg. returning an invalid response in `onERC721Received`).
 - MUST NOT be used for approval operations.
 
 #### `ERC721InsufficientApproval(address operator, uint256 tokenId)`
 
 Indicates a failure with the `operator`'s approval.
 Used in transfers.
 
-- MUST be used when operator `isApprovedForAll(owner, operator)` is false.
-- MUST be used when operator `getApproved(tokenId)` is not `operator`.
+Usage guidelines:
+
+- `isApprovedForAll(owner, operator)` MUST be false for the `tokenId`'s owner and `operator`.
+- `getApproved(tokenId)` MUST not be `operator`.
 
 #### `ERC721InvalidApprover(address approver)`
 
 Indicates a failure with the `owner` of a token to be approved.
 Used in approvals.
 
-- MUST be used for disallowed approvals from the zero address.
+Usage guidelines:
+
+- RECOMMENDED for disallowed approvals from the zero address.
 - MUST NOT be used for transfer operations.
 
 #### `ERC721InvalidOperator(address operator)`
 
 Indicates a failure with the `operator` to be approved.
 Used in approvals.
 
-- MUST be used for disallowed approvals to the zero address.
-- MUST be used for disallowed approvals to the owner itself.
+Usage guidelines:
+
+- RECOMMENDED for disallowed approvals to the zero address.
+- The `operator` MUST NOT be the owner of the approved token.
 - MUST NOT be used for transfer operations.
   - Use `ERC721InsufficientApproval` instead.
 
@@ -168,15 +194,18 @@ Used in approvals.
 Indicates an error related to the current `balance` of a `sender`.
 Used in transfers.
 
-- MUST be used when `balance` is less than `needed` for a `tokenId`.
-- MUST NOT be used if `balance` is greater than or equal to `needed` for a `tokenId`.
+Usage guidelines:
+
+- `balance` MUST be less than `needed` for a `tokenId`.
 
 #### `ERC1155InvalidSender(address sender)`
 
 Indicates a failure with the token `sender`.
 Used in transfers.
 
-- MUST be used for disallowed transfers from the zero address.
+Usage guidelines:
+
+- RECOMMENDED for disallowed transfers from the zero address.
 - MUST NOT be used for approval operations.
 - MUST NOT be used for balance or allowance requirements.
   - Use `ERC1155InsufficientBalance` or `ERC1155InsufficientApprovalForAll` instead.
@@ -186,31 +215,39 @@ Used in transfers.
 Indicates a failure with the token `receiver`.
 Used in transfers.
 
-- MUST be used for disallowed transfers to the zero address.
-- MUST be used for disallowed transfers to non-`ERC1155TokenReceiver` contracts or those that reject a transfer. (eg. returning an invalid response in `onERC1155Received`).
+Usage guidelines:
+
+- RECOMMENDED for disallowed transfers to the zero address.
+- RECOMMENDED for disallowed transfers to non-`ERC1155TokenReceiver` contracts or those that reject a transfer. (eg. returning an invalid response in `onERC1155Received`).
 - MUST NOT be used for approval operations.
 
 #### `ERC1155InsufficientApprovalForAll(address operator, address owner)`
 
 Indicates a failure with the `operator`'s approval in a transfer.
 Used in transfers.
 
-- MUST be used when operator `isApprovedForAll(owner, operator, tokenId)` is false.
+Usage guidelines:
+
+- `isApprovedForAll(owner, operator)` MUST be false for the `tokenId`'s owner and `operator`.
 
 #### `ERC1155InvalidApprover(address approver)`
 
 Indicates a failure with the `approver` of a token to be approved.
 Used in approvals.
 
-- MUST be used for disallowed approvals from the zero address.
+Usage guidelines:
+
+- RECOMMENDED for disallowed approvals from the zero address.
 - MUST NOT be used for transfer operations.
 
 #### `ERC1155InvalidOperator(address operator)`
 
 Indicates a failure with the `operator` to be approved.
 Used in approvals.
 
-- MUST be used for disallowed approvals to the zero address.
+Usage guidelines:
+
+- RECOMMENDED for disallowed approvals to the zero address.
 - MUST be used for disallowed approvals to the owner itself.
 - MUST NOT be used for transfer operations.
   - Use `ERC1155InsufficientApproval` instead.
@@ -220,7 +257,9 @@ Used in approvals.
 Indicates an array length mismatch between `ids` and `values` in a `safeBatchTransferFrom` operation.
 Used in batch transfers.
 
-- MUST be used only if `idsLength` is different from `valuesLength`
+Usage guidelines:
+
+- `idsLength` MUST NOT be `valuesLength`.
 
 ### Parameter Glossary
 
@@ -250,12 +289,12 @@ Considering this, the error names are designed following a basic grammatical str
 
 ### Actions and subjects
 
-The main actions that can be performed within a token are:
+An error is defined based on the following **actions** that can be performed on a token and its involved _subjects_:
 
 - **Transfer**: An operation in which a _sender_ moves to a _receiver_ any number of tokens (fungible _balance_ and/or non-fungible _token ids_).
 - **Approval**: An operation in which an _approver_ grants any form of _approval_ to an _operator_.
 
-The subjects outlined above are expected to exhaustively represent _what_ can go wrong in a token transaction, deriving a specific error by adding an [error prefix](#error-prefixes).
+These attempt to exhaustively represent what can go wrong in a token operation. Therefore, the errors can be constructed by specifying which _subject_ failed during an **action** execution, and prefixing with an [error prefix](#error-prefixes).
 
 Note that the action is never seen as the subject of an error.