Field Types and Tags: Page 1 of 2
Each reference is composed of a variable number of fields; and each
field is preceded by a six-character label or "tag." Some
tags are specific only to certain reference types. Each tag must be
in a specific format, and certain other rules apply to all tags. This
information is provided below.
Tag
Format
Each six-character tag must be in the following format:
Character
1
Uppercase
alphabetic character, specific to each field type. (These are described
in the following sections.)
Character
2
Uppercase
alphabetic or numeric character, specific to each field type. (These
are described in the following sections.)
Overview and Table of Contents