Faulkner does not list this type of card, but it exists.  I have just two examples in my collection, as noted below:

             C6   RP of the U.S.S. Chicago.  The card bears the notice, "Copyright by E. Muller 1899."  

             C4647a   View of the First Methodist Church and nearby  Courthouse, Mansfield, OH.  This db card has a pale blue cast like the D, FD, or PD series. 

        Are there as many as 4650 of these views?  Probably not.  It is more likely that  C4647a  relates to a number of the A series or the G series or was inserted in sequence before or after one of those numbers.  However, I have not seen enough of the C cards to know.  More importantly for this group, we need to know whether most of them are views, or topics, or novelties, or what.  Send in your answers, please.