Reply To: GREP, the need to select non-styled spaces in-between a character style

Best I can think of is searching for a not-underlined space that has nothing left and right:

(?s)(?<!.) (?!.)

(with “Underline Off” in Search Formatting.)

1. You can not use this in a GREP Style either, as it relies on the Underline Off attribute
2. Watch out, as I suspect it may also find single spaces inside tables (those also don't have a not-underlined character to its left and right).