How to … Fully and directly cite a name
The Code requires that a full and direct citation of the basionym or replaced synonym be given when nowadays publishing a new combination, name at new rank, or replacement name (Art. 41.5). Failure to do this means that the new name is not validly published.
Direct means citing the actual name, author, and place of publication, not different ones that in turn refer to the actual ones.
Full means providing all necessary details, including name, author, and place of valid publication, with page or plate reference and date.
An important point to remember is that a page or plate reference must be the page or pages on which the protologue appears. It must not be simply the page range of the whole publication (as is usual with bibliographic citations) unless the whole publication and the protologue are coextensive. If the protologue extends over two or more consecutive pages, it is common practice (and acceptable) to cite the first page on which the new name appears. In some older publications, a protologue may occur on widely separated pages; in such a case it is best to cite them all. If the publication is unpaginated, cite the page number in square brackets, e.g. “” or use another unambiguous method.
For more information, see Chapter 5 How to publish a new name in The Code Decoded.