Some PTFs are so important and so necessary that IBM labels them HIPER, which stands for High Impact, Pervasive. This type of PTF is for the kind of bug that can bring your computer down, adversely affect its performance, or produce unpredictable results.
HIPER PTFs are usually in a classification by themselves and should receive top priority in your strategy to load them into your system. Never dismiss or overlook a HIPER PTF. Some HIPER PTFs will not apply to your system, however, only you can be the judge.
For example, a HIPER PTF may be available to correct a problem with the COBOL compiler. If you do not have COBOL installed on your system or you don't use it, you do not need to worry about this PTF, no matter how important it may be in other i5 installations.
All PTFs have a cover letter, which is a document that explains the contents of the PTF you have ordered, what the PTF fixes, and other information. You should read the cover letter even if you think you know everything about the PTF.
When you request PTFs by ECS, the cover letter is placed in file QAPZCOVER (library QGPL), in a member named with a P followed by the PTF number. You can display the cover letter using the Display Physical File Member (DSPPFM) command. You can also print it using the Copy File (CPYF) command, which specifies TOFILE(QSYSPRT).