Wrong name in baptism register

 It was noted before that a wrong parent's name recorded in a baptism register can send a genealogy off in the wrong direction. 

I came across another wrongly recorded baptism recently, having done some checks to see that it wasn't a twin etc. It was for a John, the record showing the parents abode and father's occupation, also the baptism and birth date. This had to be the Charles I was looking for and who I had the GRO birth record for - same date, same parents, occupation and address.

Looking at the baptism register this record came at the top of two more John's, so it would seem the person recording simply added another John in error. A clerical error in more than one way.

I wonder how many more cases there are. Quite a few I suspect.