Maximum number of characters that one occurrence of the data field may occupy. The maximum length is not of conceptual importance in the abstract message or the HL7 coding rules. The length of a field is normative. However, in general practice it is often negotiated on a site-specific basis. It is calculated to include the component and subcomponent separators that are defined below. Because the maximum length is that of a single occurrence, the repetition separator is not included in calculating the maximum length. (See Section 2.6.5, "Repetition") In the segment attribute tables this information is in a column labeled LEN.