The phrase is "not one jot or tittle" (often mistakenly written as title), an idiom meaning that not even the smallest, most insignificant detail will be changed, omitted, or overlooked.

Origin: It comes from the King James Bible translation of Matthew 5:18:

"For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled."

Jot: Refers to iota (Greek) or yod (Hebrew: י), the smallest letter in the Hebrew alphabet.

Tittle: Refers to a tiny stroke, serif, or hook used in Hebrew script to distinguish similar-looking letters (analogous to the dot on a lowercase "i" or the cross of a "t").

Together, the phrase emphasizes absolute precision and literal adherence down to the tiniest mark on the page.