Like many of you have probably been doing, my mom and I have pulled out several jigsaw puzzles to entertain us. Mom hasn’t worked with them much before and I have been trying to give her pointers on what to look for: color, shape, comparison to picture, etc.
I found myself telling her, for instance, that she needed to be looking for a piece with two “outies” next to each other. Or in another case, we needed a piece with at least three “innies”. Sure that the internet would provide me with better terms, I “Binged” it.
Perhaps you can imagine my surprise and horror to discover that there are no agreed upon names for the various parts of a puzzle piece. I was stunned to find out that “innies and outies” were, indeed, two of the possible terms. Others are “knobs and holes”, “loops and sockets”, “tabs and slots”, “mortices and tenons”, and “keys and locks”.
Not only are there no standard terms for the parts of the pieces, there are apparently not names for the types of pieces either. For those of you not familiar with standard jigsaws, there are six basic kinds of configurations (not counting the edge pieces).
I hereby propose that since the world has not come to a previous agreement, we all decide to use the following:
First, let’s settle on “knobs and sockets”. (“Innies and outies” just reminds me too much of belly buttons.)
Second, here are the six shapes and my proposed names:
4-Socket 
3-Socket 
2-Socket or 2-Knob 
Cross 2-Socket or 2-Knob 
3-Knob 
4-Knob
Third, let’s all agree that areas on either side of the knob or socket are “shoulders”.
Now I can tell my mom I’m looking for a “3-socket piece with a long shoulder on the left side of the knob”.
I hope this post gave you all just a little chuckle in these trying times (although I wouldn’t mind at all if you decide you like my nomenclature).
Tuples and Attributes 