Article 58. Variant spellings of species-group names deemed to be identical. Species-group names established for different nominal taxa that differ in spelling only in any of the following respects and that are of the same derivation and meaning are deemed to be homonyms when the nominal taxa they denote are included in the same genus or collective group:
58.1. use of ae, oe or e (e.g. caeruleus, coeruleus, ceruleus);
58.2. use of ei, i or y (e.g. cheiropus, chiropus, chyropus);
58.3. use of i or j for the same Latin letter (e.g. iavanus, javanus; maior, major);
58.4. use of u or v for the same Latin letter (e.g. neura, nevra; miluina, milvina);
58.5. use of c or k for the same letter (e.g. microdon, mikrodon);
58.6. aspiration or non-aspiration of a consonant (e.g. oxyrhynchus, oxyrynchus);
58.7. use of a single or double consonant (e.g. litoralis, littoralis);
58.8. presence or absence of c before t (e.g. auctumnalis, autumnalis);
58.9. use of f or ph (e.g. sulfureus, sulphureus);
58.10. use of ch or c (e.g. chloropterus, cloropterus);
58.11. use of th or t (e.g. thiara, tiara; clathratus, clatratus);
58.12. use of different connecting vowels in compound words (e.g. nigricinctus, nigrocinctus);
58.13. transcription of the semivowel i as y, ei, ej or ij (e.g. guianensis, guyanensis);
58.14. use of -i or -ii, -ae or -iae, -orum or -iorum, -arum or -iarum as the ending in a genitive based on the name of a person or persons, or a place, host or other entity associated with the taxon, or between the elements of a compound species-group name (e.g. smithi, smithii; patchae, patchiae; fasciventris, fasciiventris);
58.15. presence or absence of -i before a suffix or termination (e.g. timorensis, timoriensis; comstockana, comstockiana).
Example. Because the specific names of Chrysops calidus (meaning: warm) and Chrysops callidus (meaning: clever) are derived from words of different origin and meaning, they are not homonyms even though they differ in one of the ways listed in this Article (see Article 58.7).
Recommendation 58A. Species-group names based on personal or geographical names. An author should not base a new species-group name on a personal or geographical name if another name derived from the same word or from words of the same meaning (even if differently formed) is in use in the same or an allied or associated genus (e.g. hispanus, hispanicus; moluccensis, moluccanus; sinensis, sinicus, chinensis; ceylonicus, zeylanicus).