The article discusses the nomenclature system for describing changes (mutations and polymorphisms) in DNA and protein sequences. While the current system has been largely accepted, it does not cover all types of mutations or more complex changes. The document outlines existing recommendations and suggests additional methods for describing these complex changes. It emphasizes the use of systematic names, preferred genomic reference sequences, and specific notations for deletions, duplications, and sequence variations. The authors invite further discussion and input on these suggestions, aiming to develop a uniformly accepted standard for describing sequence changes.The article discusses the nomenclature system for describing changes (mutations and polymorphisms) in DNA and protein sequences. While the current system has been largely accepted, it does not cover all types of mutations or more complex changes. The document outlines existing recommendations and suggests additional methods for describing these complex changes. It emphasizes the use of systematic names, preferred genomic reference sequences, and specific notations for deletions, duplications, and sequence variations. The authors invite further discussion and input on these suggestions, aiming to develop a uniformly accepted standard for describing sequence changes.