Slip vs flair?

as I understand, a slip is when the transmission slips (engine rpms climb, car speed stays the same)

A flair happens while the transmission is shifting.

My car has a flair between 3-4. It used to worry me, but no any more. adjusted the modulator valve. pulled the vacume line off the modulater and presto, hard shifts almost all the time. Most of what I needed was found doing a search..... Modulator valve, or trans adjustment

plenty of information on this topic.
Oh and a fluid/filter change MAY help, wont cure it but...

__________________
46 WDX Power Wagon

84 300TDT daily driver