Update ERC-7579: specify fallback authorization control

Merged by EIP-Bot.

ERCS/erc-7579.md

@@ -54,8 +54,8 @@ To comply with this standard, smart accounts MUST implement the execution interf
 interface IExecution {
  /**
  * @dev Executes a transaction on behalf of the account.
- * @param mode The encoded execution mode of the transaction. See ModeLib.sol for details
- * @param executionCalldata The encoded execution call data
+ * @param mode The encoded execution mode of the transaction.
+ * @param executionCalldata The encoded execution call data.
  *
  * MUST ensure adequate authorization control: e.g. onlyEntryPointOrSelf if used with ERC-4337
  * If a mode is requested that is not supported by the Account, it MUST revert
@@ -65,8 +65,8 @@ interface IExecution {
  /**
  * @dev Executes a transaction on behalf of the account.
  * This function is intended to be called by Executor Modules
- * @param mode The encoded execution mode of the transaction. See ModeLib.sol for details
- * @param executionCalldata The encoded execution call data
+ * @param mode The encoded execution mode of the transaction.
+ * @param executionCalldata The encoded execution call data.
  *
  * MUST ensure adequate authorization control: i.e. onlyExecutorModule
  * If a mode is requested that is not supported by the Account, it MUST revert
@@ -218,10 +218,10 @@ Smart accounts MAY implement a fallback function that forwards the call to a fal
 
 If the smart account has a fallback handler installed, it:
 
-- MUST implement authorization control
-- MUST use `call` to invoke the fallback handler
+- MUST use `call` or `staticcall` to invoke the fallback handler
 - MUST utilize [ERC-2771](./eip-2771.md) to add the original `msg.sender` to the `calldata` sent to the fallback handler
 - MUST route to fallback handlers based on the function selector of the calldata
+- MAY implement authorization control, which SHOULD be done via hooks 
 
 #### ERC-165
 
@@ -305,7 +305,7 @@ Executors MUST implement the `IModule` interface and have module type id: `2`.
 
 Fallback handlers MUST implement the `IModule` interface and have module type id: `3`.
 
-Fallback handlers that implement authorization control, MUST NOT rely on `msg.sender` for authorization control but MUST use ERC-2771 `_msgSender()` instead.
+Fallback handlers MAY implement authorization control. Fallback handlers that do implement authorization control, MUST NOT rely on `msg.sender` for authorization control but MUST use ERC-2771 `_msgSender()` instead.
 
 #### Hooks