First and foremost, it should be known that the secret and existence of the Vaizard has been guarded well. Only the Captain Commander will have knowledge of them from the get go, and NO ONE will know they exist unless they are one, or they encounter one. This is done due to the small number of Visored allowed, and to keep people from automatically saying they know everything about them. When a Shinigami suddenly grows a Hollow Mask, it should surprise you. Think back to when Ichigo first used his mask against Grimmjow. He didn't know what the fuck to thing.
Now, back to the limits on Visored themselves. ONLY 7 ARE TO BE ACCEPTED. 4 ELITES and 3 SEMI-ELITES. There may be an IC process implemented some time down the road but as of now the limit is 7 people able to register as a Visored.
To further clarify: These limits limit the Visored in WHOLE. Meaning, 7 Visored, spread across either SS OR Living World. Not 7 in each.
To further further clarify: The CC knows Visored EXIST. He knows no who each individual one is.