Add throttle interface

python/README.md

@@ -654,6 +654,36 @@ Use cases of sealing include:
 
 <https://git.grassecon.net/cicnet/erc20-demurrage-token.git>
 
+### Throttle
+
+An backend contract to limit access to a resource by time.
+
+The smart contract managing the resource calls ‘have(address)‘ on this
+contract to check if it can be made use of at the current point in time.
+This also implements [ACL](#acl).
+
+When the resource is made use of, it calls ‘poke(address)‘ method to
+register when it has been made use of.
+
+#### ERC165 Interface identifier
+
+8f5bc7bf
+
+#### Solidity interface definition
+
+    interface IThrottle {
+        // Returns true if the given address is authorized to make use of the resource at the current moment.
+        // Implements ACL
+        function have(address _address) external view returns(bool);
+
+        // Must be called when the resource is being used.
+        function poke(address _address) external returns(bool);
+    }
+
+#### Reference implementation
+
+<git://holbrook.no/eth-faucet.git> (PeriodSimple contract)
+
 ### TokenLimit
 
 Define limits of value amounts of tokens that individual addresses can