All About Pocket Knives

In the "Knife Lore" sub-forum in the "Knives Made Before the Year 1960" thread Miller Bro's opening post mentions square joint construction giving almost all knives with it a strong lasting snap.
As someone who has been plagued by disappointing snaps over the years (except AAPK knives and SAKs of course) I jumped on this comment and would like to know more e.g.
What is "square joint construction" and how to recognize it on a knife?
Is it still used on current production knives?
Can it be identified by a picture of the knife?
Is it commonly known, because it's the first time I'm meeting the term, not being as widely read on AAPK as I should.
( and now back to Miller Bro's thread )

There is some discussion of square a d flush joints here.
search.php?keywords=Square+and+flush+jo ... mit=Search

Still not sure how square joints can improve snap.
Does square joints mean square tangs?
My Case peanut has square tangs causing half stops, but the bolsters and liners are round.
I can see how square tangs can improve snap when the spring has to turn the tang corner, but my peanut still has a slight forward/back play at half stop.