The length of the string of bits must be a multiple of four when hexadecimal is used. Strings of bits can then be written by listing the named bits that are set to 1. It can be used as a place marker, but other alternatives are more common. The named information object is a node on an object identifier tree that is managed at the international level. A list of positive numbers, enclosed in braces and ordered by level starting from the root, uniquely identifies an information object at a node of the tree.
Figure illustrates the concept of an object identifier tree.
Type references and specifications of the characters in their strings are given in Figure . Also included are short labels, called tags, that are assigned to character string types for machine readability. The value notation for each character string type is a string of characters from the corresponding character set delimited by double quotation marks.