They had more than 10 rows, but I don't remember exactly how 
	many.

There were several kinds of cards.  IBM small systems had 96-column
cards (you could _print_ 128 columns, but only _punch_ 96).  They
were little things because the stuff was folded into three rows of
(7?) hole blocks.  The code on those cards was ASCII.

The old-fashioned cards were 80 columns, 12 rows.
The top row was 12, = "+".
The second row was 11, = "-".
The third row was 0, and the bottom row was 9.
Digits were coded as one hole each;
the sign of a number could be over-punched on one of the digits,
either the first or the last.
Letters were a 12-punch and a 1-to-9 for A-I,
            an 11-punch and a 1-to-9 for J-R,
          both of them  and a 2-to-9 for S-Z.
Trouble was, there were several different conventions in use for
the other characters, but it wasn't hard to read letters and digits
(and spaces = no holes punched) without the aid of the printing.