The ISO 17572 series specifies location referencing methods (LRMs) that describe locations in the context of geographic databases and that are intended for use in locating transport-related phenomena both in an encoder system and from the decoder side. This document defines what is meant by such objects and describes the reference in detail, including whether or not components of the reference are mandatory or optional, and their characteristics.

The ISO 17572 series specifies three different LRMs:

—    pre-coded LRM (pre-coded profile);

—    dynamic LRM (dynamic profile);

—    precise relative LRM (precise relative profile).

The ISO 17572 series does not define a physical format for implementing the LRM. However, the requirements for physical formats are defined.

The ISO 17572 series does not define details of the location referencing system (LRS), i.e. how the LRMs are to be implemented in software, hardware or processes.

This document specifies the following general LRM-related subjects:

—    requirements of an LRM;

—    conceptual data model for LRMs;

—    inventory LRMs (see Annex A).

This document also provides:

—    examples of conceptual model use (see Annex B);

—    a comparison of definitions with ISO/TC 211 (see Annex C).