This is used to establish a relationship between configuration items and particular exchange items. As an example, a program kit is setup as a set of particular files. This fact is expressed within the
<ablock> describing the program by referencing (via
<aref>) the
<ablock> describing the particular files.
Note that this reference can be expressed using
SGML's
ID/IDREF or by using
[class] and
[name] or both. If both mechanisms are use, they must be in sync.