I became aware of what I like to call a "plural of convenience" (POC) after I tried my hand at crossword constructing. I remember an early attempt where I had only one pesky corner remaining to be filled. The solution turned out to be simply a matter of adding an "s" to one of the words in that corner and, kaboom, the grid was complete. This is a big milestone for a fledgling constructor, believe me.
Imagine that you have invested hours on a puzzle and have filled in all of the grid except the last corner. There, one possible solution would work except that a word that fits four out of the five required squares, say FANG, is, unfortunately, a letter short of the number of squares in that slot. And then you see that by simply adding an "S" to FANG, it all falls into place. Woo-hoo!
Who could resist? I couldn't, and it appears other constructors are in the same boat. POCs are as common as dirt in crossword puzzles, even top-tier ones like the NYT or LAT.
That first experience got me hooked on POCs, but I still had a tinge of regret that I had to resort to what is essentially a SHORT CUT in constructing my puzzle.. And if I take pride in the quality of my puzzle, then taking a short cut, though convenient, will blemish my effort. It's a compromise. It's suboptimal.
Not all POCs are the same. I'm seeing four levels, from the common-as-dirt to the deal-killer.
Next: POC levels.