When may a protest be submitted?
A protest must be submitted prior to the mailing of a Notice of Allowance and the application must be pending when the examiner receives the information.
The answer to this question can be found in chapter 1900 of the MPEP. This chapter covers Protests.
The answer is from the 9th Edition, Revision 07.2015. Depending on future changes to the MPEP, the question and answer may or may not be applicable in later Editions or revisions.
This question and answer comes from section 1901 of the MPEP. The following is a brief summary of section 1901.
1901 Protest Under 37 C.F.R. 1.291
A protest is a means for a third party to challenge whether a pending application should issue. This section covers protests under 37 C.F.R. 1.291 including who may submit them, what should be filed with the protest, servicing a protest, and when to submit a protest.
Protests are ex parte matters. The examiner will not communicate further with the protester once the protest has been received. This section also briefly discusses protests and compliance issues.