International Commission on Zoological Nomenclature


Title pages

Explanatory Note on the Code

Preface to the Fourth Edition

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Chapter 1: Zoological nomenclature

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Chapter 2: The number of words in the scientific names of animals

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Chapter 3: Criteria of publication

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Chapter 4: Criteria of availability

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Chapter 5: Date of publication

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Chapter 6: Validity of names and nomenclatural acts

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Chapter 7: Formation and treatment of names

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Chapter 8: Family-group nominal taxa and their names

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Chapter 9: Genus-group nominal taxa and their names

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Chapter 10: Species-group nominal taxa and their names

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Chapter 11: Authorship

Chapter 12: Homonymy


Article 52. Principle of homonymy



52.1. Statement of the Principle of Homonymy



52.2. Operation of the Principle of Homonymy



52.3. Principle of Priority applies



52.4. Replacement of junior homonyms



52.5. Suppression of senior homonyms



52.6. Incorrect and corrected original spellings



52.7. Homonymy with names of taxa which are not animals


Article 53. Definitions of homonymy in the family group, genus group and species group.



53.1. Homonyms in the family group.



53.2. Homonyms in the genus group.



53.3. Homonyms in the species group.


Article 54. Names that do not enter into homonymy


Article 55. Family-group names



55.1. Application of the Principle of Homonymy



55.2. Homonymy from identical generic names



55.3. Homonymy from similar generic names



55.4. One-letter difference



55.5. Precedence of names at higher rank


Article 56. Genus-group names



56.1. Application of the Principle of Homonymy



56.2. One-letter difference



56.3. Precedence of genus over subgenus


Article 57. Species-group names



57.1. Application of the Principle of Homonymy to names of species and subspecies



57.2. Primary homonyms



57.3. Secondary homonyms



57.4. Subgeneric name irrelevant



57.5. Difference in spelling of generic names



57.6. One-letter difference



57.7. Precedence of names of species over those of subspecies



57.8. Exceptions


Article 58. Variant spellings of species-group names deemed to be identical


Article 59. Validity of secondary homonyms



59.1. Taxa considered congeneric



59.2. Secondary homonyms not replaced when no longer considered congeneric



59.3. Secondary homonyms replaced before 1961 but no longer considered congeneric



59.4. Reinstatement of junior secondary homonyms rejected after 1960


Article 60. Replacement of junior homonyms



60.1. Substitute names



60.2. Junior homonyms with synonyms



60.3. Junior homonyms without synonyms

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Chapter 13: The type concept in nomenclature

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Chapter 14: Types in the family group

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Chapter 15: Types in the genus group

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Chapter 16: Types in the species group

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Chapter 17: The International Commission on Zoological Nomenclature

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Chapter 18: Regulations governing this code




Appendix A: Code of Ethics

Appendix B: General Recommendations

Constitution of the ICZN