This holds the rn — the Relative Name — of the catalog's reference description of what one particular Power-On Self-Test code means, independent of any specific time it fired; it is only the final path segment identifying this object relative to its immediate parent, not the whole dn. Because a POST error-code reference entry is nested under a parent object in UCS Manager's tree, the rn is what distinguishes it from sibling entries under that same parent without repeating the full ancestor path every time. For an object whose dn is 'capabilities/post-code-1', the rn would just be the trailing segment 'post-code-1'.