The surviving texts are quite challenging. The three manuscript copies are distanced from the autograph (original manuscript) by three or four generations. As a result, the copies are plagued by errors of spelling, word division, omission, and errors of hearing (The text was apparently dictated at one point.). The text-to-text variations are not limited to the place-names, but are also significant in the intervening commentary. Thus, the bulk of the blame cannot be placed on the original author.
The most recent critical edition of the three manuscripts is that of Joseph Schnetz, Itineraria Romana, vol. II: Ravennatis Anonymi Cosmographia et Guidonis Geographica, 1942 (reprinted 1990), B G Teubner, Stuttgart.