Line numbers often come along when you copy code from a PDF, a transcript from a review system or a numbered outline from a document. The live side-by-side view shows exactly which prefixes were removed before you copy the cleaned text.
The default matcher requires punctuation, brackets or a tab after each number. This protects sentences that genuinely begin with a year or quantity. Enable Also match number + space only for plain lists such as 1 First item, and review any lines that intentionally start with digits.