:Well, even so, you still used SciFinder as the source. On a side note, the logic behind the last sentence doesn't quite hold - as I remember from discussions about systematic name referencing, IUPAC documentation is not a reliable source for IUPAC names. I know, it sounds ridiculous, but that was what was decided.    

 :Distinguising has the same reason, as for distinguishing other refferences. If you verify a statement, you wouldn't give CNN as the source, when it is located with BCC.