Also known as Lorraine or Laon notation.
Messine notation was used in north-east France, in an area including most of the archbishopric of Reims, bounded in the east by the Vosges, Eifel and Hunsrück. Towards the south and west it was not sharply detached from the area of French neumes. A special variant appeared as early as the 10th century near Lake Como.
Bent, Ian D., David W. Hughes, Robert C. Provine, Richard Rastall, Anne Kilmer, David Hiley, Janka Szendrei, Thomas B. Payne, Margaret Bent, and Geoffrey Chew. 2001 "Notation." Grove Music Online. January 20, 2001. Updated and revised July 1, 2014.
See the following example from A-KN 1013, f. 100r: