Enter a clue or pattern or both:
The Clue
Ltr. extras (4 letter answer)
The Answer
ENCS
Tags
Notes
The answer ENCS is rarely seen, appearing only about once every 1100 puzzles.
Related Clues
Business abbrs.
Env. contents
Extras in an env.
Ref. books
Ref. works
Letter attachments: Abbr.
Abbr. at the bottom of a business letter
Accompaniers of cover letters: Abbr.