If you are looking at part numbers for photodiodes from Advanced Photonix, you may see the suffix “F” at the end of your given part number.
This “F” suffix calls out the presence of a visible blocking filter.
Applicable part numbers
PDB-C134F-ND
PDB-C158F-ND
PDB-C156F-ND
PDB-C134F
PDB-C158F
PDB-C156F