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.

Protest:
Any member of the public may submit a protest, and an attorney may file a protest without naming his or her client

Unless a protester has been granted access to an original application, the protester is not entitled any information from the Office, even the mere fact that such an application exists is prohibited

A protest must be submitted prior to the mailing of a Notice of Allowance:
the application must be pending when the examiner receives the information