Immediately following the header are one or more elements. Each element will either:
- Contain the actual data
- Address the actual data
When the Eyecatcher field contains 'IRX8' and the Level field contains a value of '1', there is one element format, which either contains the data or addresses the data. New development should use only a Level of '1'; a value of 0 is deprecated. Such elements are described by the figure below.
When either the Eyecatcher field contains 'IRX8' and the Level field contains a value of '0', the Eyecatcher field contains 'IRX', or the Eyecatcher field contains 'DBCX', there are two element formats, one format contains the data and the other format addresses the data. The Element Type field indicates which; if the leftmost bit is '0' the element contains the data; if '1', the element addresses the data. Elements containing the data are described by following figure.
Elements addressing the data have one of two forms, depending upon the value of the Eyecatcher field. When the Eyecatcher field is 'IRX8' and Level = '0', the following figure describes the element; when the Eyecatcher field is 'IRX' or 'DBCX', the last figure describes the element.