Cheers, hope you get something out of this thread......
On that chart you linked to, the writer has deemed the P.Upthrust as a "Pseudo Upthrust" (where as I call them 'absorption bars').
Either way, no matter what you call them, they are a bar which appears to be an upthrust, but does nor respond as a normal upthrust would.
And the R.Upthrust is a reverse upthrust, which I refer to as a shakeout.
As you work your way through the thread, I explain more about each type of bar.
And if you want a more detailed answer, or don't understand something, let me know & i'll try to expand on what I have already written.