Al-mutashābih al-maqlūb is a special naming ambiguity created when components are reversed in order. The very same words can occur, but exchanging the positions of given name and father’s name points to a different person.
Example: “al-Aswad ibn Yazīd” and “Yazīd ibn al-Aswad” contain the elements Aswad and Yazīd in opposite positions. The words are present in both, yet the identity of the narrator and father has changed. They must not be merged simply because their components match.
Distinction: this is reversal within personal names, not automatically the separate technical issue of reversing elements of an isnād or matn. Its purpose here is accurate biographical identification.