Line Break - Combining Mark

Combining Mark is a line break class that applies to characters which typically attach to a preceding base letter without interrupting text flow, such as accents, vowel signs, or diacritical marks. These characters are treated as having no line break opportunity before or after them, meaning they cannot start a new line and do not create a break between themselves and the character they modify. This ensures that visually or phonetically connected sequences remain intact across line endings, preventing awkward splits that would separate a base glyph from its combining marks. In practice, a line break is allowed only before the base character, not between the base and its marks, so the whole cluster moves together to the next line if needed.