Mest Clear would be a Dianetic Clear.
Theta Clear refers to being stably outside the body.
Cleared Theta Clear refers to OT.
Clear OT also refers to OT: "This is a proofed up being who no longer has a bank.."
In 1978, Hubbard decided that "keyed out Clear is Clear," and that Dianetic Clears should not do PP, R6ew, and CC.
In 1970, Hubbard had written of Dianetic Clear:
"Only about 2 percent actually go clear on Dianetics. A Dianetic Clear as any other Dianetic PC now goes up through the Grades of Scientology and on to the proper Clearing Course. The Dianetic Clear of Book 1 was clear of somatics. The Book 1 definition is correct. This is the end phenomena of Dianetics as per the Classification Chart and Book 1."
A Clear of somatics Clear!
And don't forget those (actual) GPM Clears, with "one GPM Clears" and "two GPM Clears" and "three GPM Clears," and, I think, Hubbard was supposed to have made "5 GPM Clear."
And then - if I recall correctly - there was the lecture, 'The Story of Dianetics of Scientology', where Hubbard stated that he had made the first Dianetic Clears in 1947, and that these were Theta Clears. At the time of that lecture, Book 1 Clears were not regarded as being as Clear as the Clears then being produced. They were said to have been Theta Clears (stably outside the body), but later became (1970) Somatic Clears, but then with keyed out Clear being redefined as Clear (1978), and hundreds of Scientologists deciding they had "gone Dianetic Clear in 1947 after having been audited by Ron," and going "up lines" with checkbooks in hand, they became acceptable as Clears somehow...
And it goes on and on...
And it's not quite as neat as the merry modern Scientologists would like to think.
Their guru left them with a whole lot of loose-ends, each tightly shrink-wrapped in cellophane as "LRH datums."
But that's not a problem for the merry modern Scientologist, happily content in his "total certainty."
Without knowing it, his senior tech can be found in this booklet http://warrior.xenu.ca/Brainwashing-front.jpg, and it overrides all the loose-ends.
Turns out that the loose-ends are just a medium, used as a means to an end. Hubbard's system of mental-healing only needs to "work" up to a point, since it was only a front and a medium, or means, for something else.
That something else was inadvertently revealed in his 1938 'Excalibur' letter and in his 1946 'Affirmations':
"I have high hopes of smashing my name into history... [so] that it will take a legendary form... That goal is the real goal as far as I am concerned."
"Your psychology is advanced and true and wonderful. It hypnotizes people. It predicts their emotions, for you are their ruler."