Cultivar and varieties are two different things.
A
cultivar is a word combination of
cultivated and
variety. It means means that the plant has been vegetatively propagated through dividing or cloning, rather than from seed to produce a genetically unique orchid plant. Within a cultivar all the offspring are genetically identical.
A variety is a botanical rank in plant nomenclature.
To understand more about cultivar and their epithet -
Cultivar - Wikipedia, the free encyclopedia
For more on orchid naming -
Orchid Naming
and
http://www.orchidboard.com/Orchid-naming
Blc. Oriental Sunshine 'Don King' x Blc. Cherry Suisse 'Cathy' AM/AOS is the name of your orchid. It is not given a single name because this cross
may not be registered with the RHS (Royal Horticultural Society)
So they name it by the hybrid that provided the seed X pollen parent.
Anyone can check this out at the RHS site -
This is the link for a grex(hybrid) name search -
Royal Horticultural Society - Plants: The International Orchid Register
This is the link for a parentage search -
Royal Horticultural Society - Plants: The International Orchid Register
Ok now even to confuse you more
Blc = Brassiolaeliocattleya meaning it's a hybrid consisting of brassia, laelia and cattleya has now changed to Thwaitesara .. and that is how the RHS recognizes it on it's website. And the RHS doesn't require cultivar names so leave them out when checking.
If I lost you somewhere .. let me know and tell me where ..