+
+<bit>integer</bit>
+
+ The bit element represents a literal bitmask value in an expression.
+ The integer must be in the range 0..31, expanding to (1<<n) in C.
+
+<enumref ref="identifier">enum item identifier</enumref>
+
+ This element represents a reference to item of enum.
+
+<unop op="operator">expression</unop>
+
+ This element represents a unary operator, with the op attribute specifying
+ which operator. The only supported operation so far is ~, and its semantic
+ is identical to the corresponding operator in C.
+
+<sumof ref="identifier" />
+
+ This element represents a sumation of the elements of the referenced list.
+
+<popcount>expression</popcount>
+
+ This element represents the number of bits set in the expression.
+
+Documentation
+-------------
+
+ Documentation for each request, reply or event is stored in the appropriate
+ element using a <doc> element. The <doc> element can contain the following
+ elements:
+
+<brief>brief description</brief>
+
+ A short description of the request, reply or event. For example "makes a
+ window visible" for MapWindow. This will end up in the manpage NAME section
+ and in the doxygen @brief description.
+
+<description><![CDATA[longer description]]></description>
+
+ The full description. Use `` to highlight words, such as "Draws
+ `points_len`-1 lines between each pair of points…"
+
+<example><![CDATA[example code]]</description>
+
+ Example C code illustrating the usage of the particular request, reply or
+ event.
+
+<field name="name">field description</field>
+
+ The full description for the specified field. Depending on the context, this
+ is either a request parameter or a reply/event datastructure field.
+
+<error type="type">error description</field>
+
+ The full description for an error which can occur due to this request.
+
+<see type="request" name="name" />
+
+ A reference to another relevant program, function, request or event.