Too much helpfullness isn't always a good thing. Signers sometimes bring documents to Notaries with the notartial certificate information "helpfully" filled in -- but often this information proves to be wrong. The county named in the venue, for example, may be incorrect.
Fortunately, such errors are easy to fix. The Notary simply lines through any incorrect words, neatly writes in the correct information immediately above, and then initials and dates the correction.
However, a Notary may only correct information in the notarial certificate — not in the main body of the document.