Add RGB++ Assets Convention Rules doc

README.md

@@ -14,3 +14,4 @@ Documents list:
 | 01 | [RGB++ Script Standard](./docs/lockscript-design-prd-en.md) | [RGB++ 合约规范](./docs/lockscript-design-prd-cn.md) |
 | 02 | [CKB Bitcoin SPV Type Script](https://github.com/ckb-cell/ckb-bitcoin-spv-contracts/blob/master/contracts/ckb-bitcoin-spv-type-lock/README.md) | CKB BTC SPV 合约设计 |
 | 03 | [CKB Bitcoin SPV Library Design](https://github.com/ckb-cell/ckb-bitcoin-spv/blob/master/docs/Design.md) | CKB Bitcoin SPV 库的设计 |
+| 04 | [RGB++ Assets Convention Rules](./docs/RGB++-assets-convention-rules.md) | RGB++ 资产规则 |

docs/RGB++-assets-convention-rules.md

@@ -0,0 +1,66 @@
+> This document is a repost of _[_xUDT Information Convention RFC_](https://talk.nervos.org/t/xudt-information-convention-rfc/8030)_
+> post on NervosTalk forum, with minor refinements for improved consistency and readability.
+
+## Background
+
+xUDT (RGB++) assets on CKB similar to ERC20 assets on Ethereum in that they lack protocol-level uniqueness constraints for token names. 
+Considering the conventions of the Bitcoin ecosystem, Considering the conventions of the Bitcoin ecosystem, it is necessary to introduce 
+standards regarding uniqueness and length.
+
+
+## Scope
+- The following conventions cover **inscription info cell** and **unique cell**, combining the two for processing.
+  For example, each asset has a unique name among them.
+- These conventions consider only the `Symbol` and do not consider the `Name` field.
+
+```yaml
+# Unique cell
+{
+  "code_hash": "0x2c8c11c985da60b0a330c61a85507416d6382c130ba67f0c47ab071e00aec628",
+  "hash_type": "data1",
+  "out_point": {
+    "tx_hash": "0x67524c01c0cb5492e499c7c7e406f2f9d823e162d6b0cf432eacde0c9808c2ad",
+    "index": "0x0"
+  },
+  "dep_type": "code"
+}
+```
+
+## Name Conflict
+- Only the first occurrence of an asset name on-chain is acknowledged; subsequent occurrences are marked as “duplicate”.
+- Case sensitivity is ignored during duplicate comparison, for example: “Seal” is considered the same as “SEAL”.
+- Any addition of invisible characters (including spaces) to the name, regardless of whether there are similar assets,
+  is treated as a “**duplicate**”.
+- For wallets and exchanges, duplicate assets are directly hidden.
+- For browsers:
+  - “duplicate assets” are labeled as “Risk Asset - RGB++ incompatible”;
+  - non-duplicate assets are labeled as “RGB++ Compatible”;
+  - In places where the aforementioned text is too long to display, symbols such as [!] and [+] are used for marking.
+
+
+## Letters
+- For exchanges, only the ASCII visible character subset is supported.
+- For wallets and browsers, the supported character range includes:
+  - ASCII visible characters subset
+  - A subset of emojis: to be determined
+- For assets that use unsupported characters, the asset name is uniformly displayed as “INVALID”.
+
+## Length Range
+- Only assets with Symbol length of 4-5 characters are processed normally.
+- Assets falling outside this range are treated as “duplicate assets”.
+
+## Verification
+- Whitelisted assets are set to bypass the rules mentioned above.
+- To get whiltelist, To get on the whitelist, project owners should submit their token information to Cell Studio’s GitHub repository.
+  After verification, the token information will be reviewed and released. Assets on the whitelist are given priority for display
+  regardless of the above rule, and any other assets with the same name are automatically labeled as "duplicate assets".
+- As of now, the whitelist submission is not open yet. 
+
+
+## Assets Mark
+Ecosystem apps should add label / mark for every asset to provide some critical information:
+- Issuance mark: `L1 issue` / `L2 issue` to identify where the coins are issued, on Bitcoin with `rpgpp_lock` or CKB with normal lock;
+- Supply mark: `Limited supply` / `Unlimited supply` to identify whether a coin could be issued arbitrarily.
+
+  > Note: The [issue For Support tags of xudt #620](https://github.com/Magickbase/ckb-explorer-public-issues/issues/620) defines the
+  existing tags and display of xUDTs on the CKB Explorer.