A ribbon held by a person or emanating from their mouth or a corresponding scroll with text. The principle is reminiscent of today's comic books and is typical of the representation of the prophets who proclaim God's word (e.g. the scroll that Ezekiel eats in Ezk. 3:1-3).
We have been running a specialist store for facsimiles for over 10 years in Regensburg's Old Town, just opposite the "Schottenportal" of the Romanesque Scots Monastery of St. Jacob at Jakobstraße 6.