Enter a clue or pattern or both:
The Clue
One concern of a proofreader (11 letter answer)
The Answer
PUNCTUATION
Tags
Notes
The answer PUNCTUATION is so rare that it appears less than once every 2500 puzzles.
Definition
PUNCTUATION as a noun:
1. something that makes repeated and regular interruptions or divisions
2. (punctuation, punctuation mark) = the marks used to clarify meaning by indicating separation of words into sentences and clauses and phrases
3. the use of certain marks to clarify meaning of written material by grouping words grammatically into sentences and clauses and phrases