tavuviiva

Tavuviiva is a Finnish term for the typographic mark used to indicate where a word may be broken at the end of a line. It corresponds to the concept known in English as a soft hyphen and is used to improve text justification by signaling potential breakpoints within long or compound words. The name literally means “syllable dash” in Finnish.

In digital text, the tavuviiva is encoded as the Unicode character U+00AD, the SOFT HYPHEN. The symbol is typically invisible in a rendered line until a line break occurs at that point; if the line does not break there, the character remains hidden. In HTML and other markup languages, it can be inserted with the soft hyphen entity (­) or the numeric reference ­.

Usage and guidelines for the tavuviiva vary with typesetting systems and languages. It is particularly relevant for Finnish, which features long compound words and agglutinative morphology, where appropriate syllable boundaries help maintain readable line breaks. Style guides generally advise using hyphenation sparingly and avoiding breaks in proper names, numbers, or visually prominent sequences, while allowing breaks at natural morphological boundaries when needed to improve justification and text flow.

Related concepts include hyphenation, the regular hyphen, and the general practice of line breaking in typography. The tavuviiva serves as a flexible indicator of permissible breakpoints, enabling clearer and more aesthetically pleasing text layouts across both print and digital media.