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

Chapter 6: Validity of names and nomenclatural acts


Article 23. Principle of priority



23.1. Statement of the principle of priority



23.2. Purpose



23.3. Application to synonymy



23.4. Application to homonymy



23.5. Application to spellings



23.6. Application to nomenclatural acts



23.7. Application to collective groups and ichotaxa



23.8. Application to species-group names established on hybrids



23.9. Reversal of precedence



23.10. Erroneous reversal of precedence



23.11. Application of strict priority desired



23.12. Names rejected under former article 23b


Article 24. Precedence between simultaneously published names, spellings or acts



24.1. Automatic determination of precedence of names



24.2. Determination by the First Reviser

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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

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Chapter 12: Homonymy

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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