Article 60. Replacement of junior homonyms
A junior homonym [Art. 53] must be rejected and replaced either by an available and potentially valid synonym [Art. 23.3.5] or, for lack of such a name, by a new substitute name [Art. 60.3]. For unused senior homonyms see Article 23.9; for the replacement of homonymous family-group names see Articles 39 and 55.3; and for the replacement of secondary homonyms in the species group see Article 59.
60.2. Junior homonyms with synonyms
If the rejected junior homonym has one or more available and potentially valid synonyms, the oldest of these becomes the valid name of the taxon [Art. 23.3.5] with its own authorship and date.
60.2.1. Such a name can be retained as a valid name in place of a junior homonym only as long as it is regarded as a synonym of the latter.
60.3. Junior homonyms without synonyms
If the rejected junior homonym has no known available and potentially valid synonym it must be replaced by a new substitute name, with its own author and date; this name will then compete for priority with any synonym recognized later.
Recommendation 60A. Desirability of objective replacement. Unless the name-bearing type of the nominal taxon denoted by the rejected junior homonym is taxonomically inadequate (e.g. as described in Article 75.5 or, in the case of a genus-group homonym, the type species is poorly defined), authors are advised to use that same type to establish a new replacement name (nomen novum) as an objective replacement [Arts. 67.8, 72.7].