أَوْ مَا لَمْ يُشْتَرَطْ فِيهِ ذَلِكَ، وَاجْتَمَعَ مَعَ سَبَبٍ وَاحِدٍ فَقَطْ، وَهُوَ الْعَلَمُ الْمَعْدُولُ وَوَزْنُ الْفِعْلِ
Translation: Or cases where the author treats proper-name status together with one further cause, such as ʿadl (a shifted form) or a verbal pattern.
When the name ceases to function as a proper name, that element disappears. If only one cause remains, the noun can again be fully declinable.