Dieses Zeichen ist ein Nonspacing Mark und erbt seine Schrift-Eigenschaft vom vorhergehenden Zeichen.
Das Zeichen ist keine Zusammensetzung. Seine Weite in ostasiatischen Texten wird vom Kontext bestimmt. Es kann weit oder schmal sein. In bidirektionalem Text handelt es als Nonspacing Mark. Bei einem Richtungswechsel wird es nicht gespiegelt. U+030F verbietet einen Zeilenumbruch vor sich.
Die Wikipedia hat die folgende Information zu diesem Codepunkt:
The double grave accent (◌̏) is a diacritic used in scholarly discussions of the Serbo-Croatian and sometimes Slovene languages. It is also used in the International Phonetic Alphabet.
In Serbo-Croatian and Slovenian, double grave accent is used to indicate a short falling tone, though in discussion of Slovenian, a single grave accent is also often used for this purpose. The double grave accent is found in both Latin and Cyrillic; however, it is not used in the everyday orthography of any language, only in discussions of phonology.
In the International Phonetic Alphabet, the double grave accent is used to indicate extra-low tone.
The letters a, e, i, o, r, u, and their Cyrillic equivalents а, е, и, о, р, and у can all be found with the double grave accent. Unicode provides precomposed characters for the uppercase and the lowercase Latin letters but not the Cyrillic letters. The Cyrillic letters can be formed using the combining character for the double grave, which is located at U+030F. The combining character can also be used with IPA vowel symbols, if necessary.