Just kidding. As I write and edit quite a number of Wikipedia articles on Buddhism (I wrote the Mantra of Light article above almost in entirety), I know how poorly researched it is. People write flowery statements and then don’t back them up with research. I should edit that above and mention the kechien kongo. That part is pretty well known in Shingon Buddhism, so I am surprised it’s not mentioned.

Although the person could be referring to the fact that the inner rituals are for ordained priests only, but then again they’re not clearly stating that, and it should be further clarified.

“In order to accurately reproduce this innermost realization it is necessary to be initiated into the practice by a qualified teacher.”

It does not clearly state that this is for priests versus lay practioners. However, Wikipedia is notorious for inaccuracies.