Nita
They would be pretty much as Nanny Jan describes, the format for marriage registers was laid down by Hardwicke's Marriage Act of 1753, and the printed forms that most parishes used from that date did not allow space for extra detail, though once in a while you might find an extra note squeezed in. Your best hope of extra infromation would be if the marriage was by licence (most were after banns), in which case you might find some extra details on the allegation for the licence itself. (The licence was the paper given to the bride or groom, the allegation was the part that was kept by the issuing authority).
Mean_genie