These are endorsements, or extra coverage, on the loan policy. These are Pennsylvania filed endorsements. Number 100 covers the lender for issues related to unknown violations of restrictive covenants, conditions, etc. Number 300 covers the lender for unknown matters that might have been discovered by a current up to date survey of the premises. Number 900 covers the lender for environmental issues aka ALTA 8.1.
These are the most typical endorsements required by mortgage lenders in Pennsylvania and they each run $50.