The convention is to place your educational degree first, your state issued title next, and your certification last.
e.g. John/Mary Doe, MSN, APN, FNP.
Your board cert letters follow, -C for AANP and -BC for ANCC.
If your terminal degree is a doctorate, it should be listed last and you should eliminate the masters degree if you have a doctorate.
The MSN is not necessarily listed or needed and is fairly redundant, as virtually every NP in the nation is
prepared at the graduate level.
If you'd like to use your peds nurse certification, by all means do it, but place it before
your NP credentials: John Doe, MSN, APN, CPN, FNP. Just be aware that too many credentials and degrees
after your name gets confusing to patients and colleagues alike - and can also be viewed as
title envy or insecurity. Better to leave in your highest credentials and drop your RN credentials,
UNLESS you're appearing as an expert witness - then I'd list every credential I have, particularly in a court document.
I sign my name in charts and documents as XXX, APN, FNP-BC.
My email signature says XXX, Nurse Practitioner, Board Certified in Family Practice
If I had a doctorate, for the sake of brevity, I would write it this way: XXX, FNP-BC, PhD.
Add the APN title when necessary.
Hope this helps.