Word Break - Alphabetic letter
Alphabetic letter is a classification for characters that function as full letters in writing systems, meaning they are used to form words and typically have both uppercase and lowercase forms where applicable. This value applies to letters from scripts like Latin, Greek, Cyrillic, Hebrew, and Arabic, as well as to modifier letters and certain letterlike symbols, but it excludes digits, punctuation, and ideographs like Chinese characters. In text segmentation, this value treats such letters as part of a single word unit, so they break only at word boundaries defined by spaces, punctuation, or other non-letter characters. It also interacts with adjacent characters of the same class to form continuous runs for line breaking and cursor movement, but it does not include numbers or underscores, which have their own distinct behaviors.