What are the Master Table validations required for below fields

Hi,

I have created a selection screen with following fields.

Can anybody tell me what are the exact master table vaidation i can do for the same!

<b>Order Type[VBAK-AUART],

Order Number[VBAK-VBELN],

Customer PO #[VBKD-BSTKD],

Sold-to Party No[VBPA-PARVW - SP as key],

Ship-to Party No[VBPA-PARVW - SH as key],

Division[VBAK-SPART].</b>

Agaist which master tables i need to vaidate above fields!

Also please clarify what is meant by [SP as Key] & [SH as key]! Is it needs to be defaulted!

Thanks in advance.

Thanks,

Prasad.