Update ERC-5521: Move to Final

Merged by EIP-Bot.

ERCS/erc-5521.md

@@ -4,8 +4,7 @@ title: Referable NFT
 description: An ERC-721 extension to construct reference relationships among NFTs
 author: Saber Yu (@OniReimu), Qin Wang <[email protected]>, Shange Fu <[email protected]>, Yilin Sai <[email protected]>, Shiping Chen <[email protected]>, Sherry Xu <[email protected]>, Jiangshan Yu <[email protected]>
 discussions-to: https://ethereum-magicians.org/t/eip-x-erc-721-referable-nft/10310
-status: Last Call
-last-call-deadline: 2024-06-07
+status: Final
 type: Standards Track
 category: ERC
 created: 2022-08-10
@@ -128,7 +127,7 @@ interface TargetContract is IERC165 {
 ### Is this event informative enough? 
 `UpdateNode`: This event disseminates crucial information, including the rNFT ID, its owner, and lists of contract addresses/IDs with rNFTs referring to or referred by the subject rNFT. This data set enables stakeholders to efficiently manage and navigate the complex web of relationships inherent in the rNFT ecosystem.
 
-Implementers are free to choose to use a struct (a **RECOMMENDED** struct is given in the Reference Implementation), or several separate mappings, or whatever other storage mechanism. Whichever mechanism chosen has no observable effect on the behaviour of the contract, as long as its output can fulfill the `UpdateNode` event.
+Implementers are free to choose to use a struct (a recommended struct is given in the Reference Implementation), or several separate mappings, or whatever other storage mechanism. Whichever mechanism chosen has no observable effect on the behaviour of the contract, as long as its output can fulfill the `UpdateNode` event.
 
 ### Why `createdTimestampOf`?
 `createdTimestamp`: A key principle of this standard is that an rNFT should reference content already accepted by the community (a time-based sequence known by participants). Global timestamps for rNFTs are thus essential, serving to prevent conflicting states (akin to concurrency issues in transaction processing and block organization). We define a block-level timestamp where `createdTimestamp = block.timestamp` Note that, given that the granularity of references is tied to the block timestamp, it is impractical to discern the order of two rNFTs within the same block.
@@ -149,14 +148,14 @@ Test cases are included in [ERC_5521.test.js](../assets/eip-5521/ERC_5521.test.j
 
 ## Reference Implementation
 
-The **RECOMMENDED** implementation is demonstrated as follows:
+The recommended implementation is demonstrated as follows:
 
-- `Relationship`: a structure that contains `referring`, `referred`, `referringKeys`, `referredKeys`, `createdTimestamp`, and other customized and **OPTIONAL** attributes (i.e., not necessarily included in the standard) such as `privityOfAgreement` recording the ownerships of referred NFTs at the time the Referable NFTs (rNFTs) were being created or `profitSharing` recording the profit sharing of `referring`.
+- `Relationship`: a structure that contains `referring`, `referred`, `referringKeys`, `referredKeys`, `createdTimestamp`, and other customized and optional attributes (i.e., not necessarily included in the standard) such as `privityOfAgreement` recording the ownerships of referred NFTs at the time the Referable NFTs (rNFTs) were being created or `profitSharing` recording the profit sharing of `referring`.
 - `referring`: an out-degree indicator, used to show the users this NFT refers to;
 - `referred`: an in-degree indicator, used to show the users who have refereed this NFT;
 - `referringKeys`: a helper for mapping conversion of out-degree indicators, used for events;
 - `referredKeys`: a helper for mapping conversion of in-degree indicators, used for events;
-- `createdTimestamp`: a time-based indicator, used to compare the timestamp of mint, which **MUST NOT** be editable anyhow by callers.
+- `createdTimestamp`: a time-based indicator, used to compare the timestamp of mint, which should not be editable anyhow by callers.
 - `referringOf` and `referredOf`: First, the current `referringOf` and `referredOf` allow cross-contract looking up, while this cannot be done by directly accessing `_relationship`. Secondly, only if privacy is not a concern, making `_relationship` public simplifies the contract by relying on Solidity’s automatically generated getters. However, if you need to control the visibility of the data, keeping the state variable private and providing specific getter functions would be the best approach.  For example, if `_relationship` includes details about specific users’ interactions or transactions or some private extensible parameters (in the updated version, we specifically highlight the `Relationship` can be extended to meet different requirements), always making this data public could reveal users’ behavior patterns or preferences, leading to potential privacy breaches.
 - `convertMap`: This function is essential for retrieving the full mapping contents within a struct. Even if `_relationship` is public, The getters only allow retrieval of individual values for specific keys. Since we need comprehensive access to all stored addresses, `convertMap` is necessary to fulfill our event emission requirements.