The first issue is presentation formatting, where the problem is formatting
the different types of data that application programs compute
on, such that they can be transmitted over a network and interpreted
correctly by the receiver. Data types such as integers, floating-point numbers,
character strings, arrays, and structures must be encoded in some
intelligible way. This involves both translating between machine and network
byte order and linearizing compound data structures. We outlined
the design space for presentation formatting and discussed four specific
mechanisms that fall on different points in this design space: XDR, ASN.1,
NDR, and the increasingly important XML.