Blavatsky
Original sense
Initiation is a real, graded expansion of consciousness, traditionally guarded by schools, involving tests of character and occult knowledge. It is not a ceremony you can purchase, and the true mysteries, she claimed, were never fully written down. Public ‘initiations’ are at best symbolic.
There is no such thing as an initiate who has not been tried in the fire of his own lower nature.
Later Theosophy (Leadbeater, Bailey) published elaborate initiation charts (first through fifth, solar, planetary). Blavatsky was far more reserved about grades and names.