15, 25, 37 and 50 pin varieties. The D-sub designation defines the physical structure of the connector, not the purpose of each line. In the international DIN 41625 standard, the letters A through ...

A with 15, B with 25, C with 37, D with 50, and E with 9. This convention is often followed by a P (plug) or S (socket) - sometimes and M and F are used - to identify the gender of the part. For ...