Thank you both for the replies. I have been mistakenly using
#desc when I should be using
desc. However performing these searches
desc:empty,
desc:_empty,
desc:false right now results in no matching records displayed.
Following BR's suggestion to use the Quality Check plugin, I get a result stating there are 1903 records which have no comments. Sampling those 1903 records, I'm getting the expected results; only records with absolutely nothing in the built-in desc field are listed.
But something is wrong. There appears to be a constant null result on any
desc search, regardless of keyword and/or search term used.
This is on a database of Manga. The 3rd Party website where I get info is
Bleach's entry at MangaUpdates, is one example entry. Note at the end of the Manga Updates' Description section (top left) of the page, it mentions an award called "Shogakukan". I figured that word was sufficiently unique to perform a quick search with a small number of results. I tried, just to be thorough, desc:Shogakukan, desc:"Shogakukan", and desc:"=Shogakukan"... and each search showed that there was no matching records - despite having 84 Bleach related records, 81 of which include complete copies of the Bleach page from Manga Updates. So there should have been an 81 record match to that search.
Yet I'm getting nothing. I'm going to update Calibre (I'm using v2.40), double check, and then update this message.