hematology - What are the blood groups for human beings?

Human blood groups are of 4 types with negative and positive of each types (Wikipedia). But according to this forum thread there are some other types too:

A+,A-,B+,B-,O+,O-,AB+,AB-,A1+,A1-,A2+,A2-,A1B+,A1B-,A2B+,A2B-

I'm going to make software for blood donation, where I need to put a dropdown list of actual blood types. I had intended to use:

[ Select Blood Group V ]
[ O Negative           ]
[ O Positive           ]

[ A Negative           ]
[ A Positive           ]
[ B Negative           ]
[ B Positive           ]
[ AB Negative          ]
[ AB Positive          ]

But now I am uncertain whether this is appropriate. What is the most suitable list of blood types for donors?