Each of the sections that follow describes a data type defined in the XDR standard, shows how it is declared in the language, and includes a graphic illustration of its encoding.

For each data type in the language we show a general paradigm declaration. Note that angle brackets (< and >) denote variablelength sequences of data and square brackets ([ and ]) denote fixed-length sequences of data. "n", "m" and "r" denote integers. For the full language specification and more formal definitions of terms such as "identifier" and "declaration", refer to section 5: "The XDR Language Specification".

For some data types, more specific examples are included. A more extensive example of a data description is in section 6: "An Example of an XDR Data Description".

- 3.1 Integer
- 3.2. Unsigned Integer
- 3.3 Enumeration
- 3.4 Boolean
- 3.5 Hyper Integer and Unsigned Hyper Integer
- 3.6 Floating-point
- 3.7 Double-precision Floating-point
- 3.8 Quadruple-precision Floating-point
- 3.9 Fixed-length Opaque Data
- 3.10 Variable-length Opaque Data
- 3.11 String
- 3.12 Fixed-length Array
- 3.13 Variable-length Array
- 3.14 Structure
- 3.15 Discriminated Union
- 3.16 Void
- 3.17 Constant
- 3.18 Typedef
- 3.19 Optional-data
- 3.20 Areas for Future Enhancement