If they applied for notes before Submitting the application, What did they select for :
What type of record would you like to access?
Also it might also depend on how they became PR, the process and checks involved then etc.
If they were previously cleared for background Checks and no adverse history exists since becoming PR until now, they should apply for Citizenship as per normal.
often times there are notes on our file which might not necessarily be relevant to the present application, however what was stated in above paragraph remains.