diff --git a/docs/built-in-functions.rst b/docs/built-in-functions.rst
index fa1b399803..a76036fe0a 100644
--- a/docs/built-in-functions.rst
+++ b/docs/built-in-functions.rst
@@ -229,3 +229,39 @@ Takes two elliptical curves and multiplies them together.
 
     :output d: either bytes32, num128, or address
     """
+
+**RLPList**
+---------------
+::
+
+  def _RLPList(a, b) -> c:
+    """
+    :param a: encoded data
+    :type a: bytes
+    :param b: RLP list
+    :type b: list
+
+    :output c: LLLnode
+    """
+
+Takes encoded RLP data and an unencoded list of types. Usage::
+
+  vote_msg: bytes <= 1024 = ...
+   
+  values = RLPList(vote_msg, [int128, int128, bytes32, bytes, bytes])
+
+  var1: int128 = values[0]
+  var2: int128 = values[1]
+  var3: bytes32 = values[2]
+  var4: bytes <= 1024 = values[3]
+  var5: bytes <= 1024 = values[4]
+
+Note: RLP decoder needs to be deployed if one wishes to use it outside of the Vyper test suite. Eventually, the decoder will be available on mainnet at a fixed address. But for now, here's how to create RLP decoder on other chains:
+
+\1. send 6270960000000000 wei to 0xd2c560282c9C02465C2dAcdEF3E859E730848761
+
+\2. Publish this tx to create the contract::
+  
+   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
+
+\3. This is the contract address: 0xCb969cAAad21A78a24083164ffa81604317Ab603