Namecoin isn't actually a "registrar" in this case, but the canonical blockchain used with Passcard.info. You can think of it as the self-registration alternative. The Namecoin link is definitely a conversion blackhole. This would be a bit better: https://github.com/namesystem/namesystem/wiki/Namecoin
Onename, which has designed Passcard.info, is attempting to standardize the identity protocol by decoupling it from its core identity registration service.
A somewhat fragmented space, here's an example of another blockchain based identity protocol using the id/* namespace on Namecoin: https://nameid.org/?name=domob
That link isn't any better than the first. Passcard bills itself as a service for non-technical users. Any and all sign-up links should point to clear, easy-to-follow, step-by-step instructions. Neither the Namecoin front page nor a wiki page about important Namecoin esoterica fit that bill. :)
Note: I'm not trying to shit on the project (just as I'm not trying to shit on your comment). I'm sure it was a substantial amount of work, and is at an early stage in its development. If, however, one is launching a project that has non-technical folks as its audience, appropriate documentation is just as important as the software.
Onename, which has designed Passcard.info, is attempting to standardize the identity protocol by decoupling it from its core identity registration service.
A somewhat fragmented space, here's an example of another blockchain based identity protocol using the id/* namespace on Namecoin: https://nameid.org/?name=domob