What do the boxes in the top right corner of the application mean?

Question: What do the boxes R, D, O, and DP shown at the top right corner of page 1 mean? Also, what is required for End# and Exp# within the same box?

Answer: The small box in the top right corner of passport application Form DS-11 is not to be filled in by the applicant but by the acceptance agent at the location where you submit the form.

This can be either a passport application acceptance facility (most frequently located in post offices) or a regional passport agency.