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diff --git a/docs/contracts.rst b/docs/contracts.rst
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@@ -485,6 +485,108 @@ value types and strings.
 Functions
 *********
 
+Function Parameters and Return Variables
+========================================
+
+As in JavaScript, functions may take parameters as input. Unlike in JavaScript
+and C, functions may also return an arbitrary number of values as output.
+
+Function Parameters
+-------------------
+
+Function parameters are declared the same way as variables, and the name of
+unused parameters can be omitted.
+
+For example, if you want your contract to accept one kind of external call
+with two integers, you would use something like::
+
+    pragma solidity >=0.4.16 <0.6.0;
+
+    contract Simple {
+        uint sum;
+        function taker(uint _a, uint _b) public {
+            sum = _a + _b;
+        }
+    }
+
+Function parameters can be used as any other local variable and they can also be assigned to.
+
+.. note::
+
+  An :ref:`external function<external-function-calls>` cannot accept a
+  multi-dimensional array as an input
+  parameter. This functionality is possible if you enable the new
+  experimental ``ABIEncoderV2`` feature by adding ``pragma experimental ABIEncoderV2;`` to your source file.
+
+  An :ref:`internal function<external-function-calls>` can accept a
+  multi-dimensional array without enabling the feature.
+
+.. index:: return array, return string, array, string, array of strings, dynamic array, variably sized array, return struct, struct
+
+Return Variables
+----------------
+
+Function return variables are declared with the same syntax after the
+``returns`` keyword.
+
+For example, suppose you want to return two results: the sum and the product of
+two integers passed as function parameters, then you use something like::
+
+    pragma solidity >=0.4.16 <0.6.0;
+
+    contract Simple {
+        function arithmetic(uint _a, uint _b)
+            public
+            pure
+            returns (uint o_sum, uint o_product)
+        {
+            o_sum = _a + _b;
+            o_product = _a * _b;
+        }
+    }
+
+The names of return variables can be omitted.
+Return variables can be used as any other local variable and they
+are initialized with their :ref:`default value <default-value>` and have that value unless explicitly set.
+
+You can either explicitly assign to return variables and
+then leave the function using ``return;``,
+or you can provide return values
+(either a single or :ref:`multiple ones<multi-return>`) directly with the ``return``
+statement::
+
+    pragma solidity >=0.4.16 <0.6.0;
+
+    contract Simple {
+        function arithmetic(uint _a, uint _b)
+            public
+            pure
+            returns (uint o_sum, uint o_product)
+        {
+            return (_a + _b, _a * _b);
+        }
+    }
+
+This form is equivalent to first assigning values to the
+return variables and then using ``return;`` to leave the function.
+
+.. note::
+    You cannot return some types from non-internal functions, notably
+    multi-dimensional dynamic arrays and structs. If you enable the
+    new experimental ``ABIEncoderV2`` feature by adding ``pragma experimental
+    ABIEncoderV2;`` to your source file then more types are available, but
+    ``mapping`` types are still limited to inside a single contract and you
+    cannot transfer them.
+
+.. _multi-return:
+
+Returning Multiple Values
+-------------------------
+
+When a function has multiple return types, the statement ``return (v0, v1, ..., vn) can be used to return multiple values.
+vn)`` can return multiple values.  The number of components must be
+the same as the number of return types.
+
 .. index:: ! view function, function;view
 
 .. _view-functions: