Hi, Mack, it depends in the board that you are using, there are 4 levels of priority (from 0 to 3) that you can use,being 0 the one that has more priority, in the reference manual there is a register that you can configure to set the priorities of the interruptions the (IPRx). in the first file that Iva Sent to you, in the page 6 there is some information about the priorities.
For example in the KL25z in the reference manual, P.52 you can find the priority levels for the Ports and a Table that explains it.
Kl24z-Reference Manual.
Regards.
-Jonathan