Do not enter your or your employer’s contributions to your regular pension plan (RPP) in the RRSP Contributions & Deduction section.

Confusingly, an RPP is not the same as a pooled registered pension plan (PRPP).

You will get a deduction for your RPP contributions on line 20700. This amount comes from your T4 or T4A slip, or from the RPP Contributions Not Showing on a T4 or T4A section.