The most common and most likely answer to this crossword clue is the 3 letter word REQ which also is the latest solution we found used in New York Times in 2014.
Not optional: Abbr crossword clue answers
Here's a list of possible crossword answers ranked by the most likely to least likely.
| Answer | Likelyness | Letters | 
|---|---|---|
| REQ | 75 % | 3 | 
| REQD | 25 % | 4 | 
Words with a meaning similar to the clue: Not optional: Abbr
These words may or may not be a possible solution to this crosswords clue.- var
 - facultative
 - elective
 - essential
 - imperative
 - mandatory
 - necessary
 - needed
 - obligatory
 - votive
 - must
 - need
 
More crossword clues leading to the same solutions
Here's a few more crossword clues - all leading to the identical solution
More clues leading to the result REQ
- Written order: Abbr.
 - Not optional: Abbr.
 - Necessary: Abbr.
 - Not opt.
 - Necessary (abbr.)
 - Mil. supplies order
 - Need (abbr.)
 - Mil. demand for supplies
 - Strictly mandated (abbr.)
 - Opt. opp.