document

contracts/token/ERC20/extensions/ERC20Votes.sol

@@ -28,6 +28,12 @@ abstract contract ERC20Votes is ERC20, Votes {
 
     /**
      * @dev Maximum token supply. Defaults to `type(uint208).max` (2^208^ - 1).
+     *
+     * This maximum is enforced in {_update}. It limits the total supply of the token, which is otherwize a uint256, so
+     * that checkpoints can be stored in Trace208 structure used by {{Votes}}. Increasing this value will not remove
+     * the underlying limitation, and will the {_update} to fail because of a math overflow in {_transferVotingUnits}.
+     * An override could be used to further restrict the total supply (to a lower value) if additional logic requires
+     * it. When resolving override conflicts on this function, the minimum should be returned.
      */
     function _maxSupply() internal view virtual returns (uint256) {
         return type(uint208).max;