وَحَرَكَاتُهُ تُسَمَّى ضَمًّا وَفَتْحًا وَكَسْرًا، وَسُكُونُهُ وَقْفًا.
Translation: Its fixed final movements are called ḍamm, fatḥ, and kasr; its fixed sukūn is termed waqf in the book.
These terms describe a built ending, not necessarily nominative, accusative, or genitive case. This is the distinction emphasized by the text.