CardType parameter is documented in the «AlphaHPP» → «Paypage Request Reference» → «Request a Paypage Session» table:
The type of card selected by the user e.g.
MASTERor allows merchant to prepopulate reduced set of cards to display by using comma delimiter.
Current values supported:
Is any practical sense to limit a buyer to particular bank card brands by the
CardType parameter, and disallow to pay with a card of another brand?
In my experience, it really can have a sense for some payment service providers.
For example, Stripe disallows the non-USA merchants to accept the JCB, Discover, and Diners Club bank cards.
But does it have a sense in the AlphaCommerceHub?
E.g. does AlphaCommerceHub allow an Australian-based merchant to accept the JCB, Discover, and Diners Club bank cards?