What is the “Beilstein Preferred Registry Number (BPR)”?
The BPR is the single CAS registry number that has been selected as the best choice for a compound from the one or more registry numbers which might be present in the database. The BPR is NOT always present, and is selected from the following criteria: • If there’s only one RN available from all sources, this will be the BPR • Some compounds have one or more registry numbers assigned by the CAS. If Beilstein has one of these RNs on record in its file, this will be the BPR. If, however, Beilstein has *different* RNs in its field, the compound will not be given a BPR and only the CAS value will appear in the RN field. • If a compound has not received a registry number from CAS and Beilstein has several RNs in its own field, these RNs appear in the compound record but a BPR will not be given.
