This document presents the Approved Lists of Bacterial Names, established by an Ad Hoc Committee of the International Committee on Systematic Bacteriology (ICSB) and published in 1980. The project aimed to compile valid bacterial names based on adequate descriptions and the availability of type, neotype, or reference strains. Names included were either validly published before January 1, 1978, or published through October 1979 in the International Journal of Systematic Bacteriology. The compilation involved extensive consultation with taxonomic subcommittees and specialist advisers worldwide. The document details procedures for handling nomenclatural issues, strain designations from international culture collections, and clarifications on name retention, deletion, and revival. All strains submitted as type, neotype, or reference strains were elevated to type status. Some names lacking available strains were retained to preserve genus or species status. The committee emphasized its nomenclatural rather than taxonomic role. January 1, 1980, became the new priority date for bacterial nomenclature, replacing the previous date of May 1, 1753, establishing a definitive baseline for future bacterial taxonomy and nomenclature.

Key findings

• The Approved Lists established January 1, 1980, as the new priority date for bacterial nomenclature, replacing May 1, 1753, creating a new baseline for naming validity.
• Names were selected based on adequate description and availability of type, neotype, or reference strains in recognized culture collections worldwide.
• The committee elevated all submitted nomenclatural type, neotype, and reference strains to official type strain status to provide clear nomenclatural foundation.
• Some names lacking available strains were retained when necessary to preserve genus or type species status under nomenclatural rules.
• The document clarifies that names not appearing in the Approved Lists are nomenclaturally invalid as of January 1, 1980, and may only be revived following specific nomenclatural procedures.