A protestor must have a good reason as to why the pending application should not be allowed. Valid protest reasons include; information concerning the patentability of the subject matter (i.e., if it was on sale or published more than a year before the filing of the application) or if the inventorship is inaccurate.

The basics of protests should be understood. It is important to know the differences between protests, reexaminations, reissues, interferences and appeals. The PTO will try to incorporate these topics into questions in a confusing manner, so be sure to understand the differences.