Ten general principles guided the original IOC recommendations of the English names of world birds.  Formulation of these principles and achieving consensus for their adoption dominated the early years of the original IOC English Names Project.  They are:

1. Each species should have one name only >>
2. A species name must be unique >>
3. Anglicized names are acceptable >>
4. Established names should prevail >>
5. Local names should not have priority >>
6. Offensive names should be changed >>
7. Patronyms are acceptable without bias for or against >>
8. Simplicity and brevity are virtues >>
9. Use of the word “island” will be limited >>
10. Species in the same genus may have different group names >>

1. ONE NAME: Every taxon shall have only one recommended International English name.

This principle appears obvious and easy to state, but it presented serious problems especially for members of the Nearctic and Palearctic subcommittees, who favored one or the other of the different names used in Great Britain or the United States for the same taxa. We consistently rejected suggested compromises that would list alternative names (e.g., Bearded Vulture or Lammergeier, Little Auk or Dovekie).

2. UNIQUE NAME: The name of each taxon must be different from the names of all other (Bird) taxa.

This principle generated the corollary that where two or more taxa had basically the same name, modifiers would have to be added to distinguish them. Thus three “Black Ducks” had to be named American, African, and Pacific and two “White Ibises” American and Australian.A related rule is that the full name of one species should not be included in the longer name of another species. This rule prohibited a pair of names like Black-headed Gull and Great Black-headed Gull, forcing the initial adoption of Common Black-headed Gull. Adoption of Pallas’s Gull for I. ichthyaetus in response to good feedback allowed us to drop “Common” and return to the preferred traditional English name.

3. USE OF NONENGLISH WORDS: Non-English words that have been in common use for a substantial time have in effect become “English.”

Usage would govern. The established names of many birds use their taxonomic name from another language. Just because a bird’s long-standing name was in fact its taxonomic name, it did not have to be changed to an English word. Thus names like Junco, Vireo, and Rhea have been retained. This is of particular significance in names of tropical birds, many of which are the taxon’s generic names (e.g., Elaenia , Jacana , Dacnis , Attila , Myzomela ). The committee rejected the idea of a wholesale renaming of these taxa, while recognizing that ongoing revisions of bird genera will continue to create odd mismatches.The committee likewise accepted a large number of Spanish words on the basis of long usage (e.g., Doradito, Monjita, Tapaculo) and even a number of Amerindian ones (e.g., Quetzal, Cacique). These latter two names are now in such wide usage that they appear in the Oxford English Dictionary.The most troublesome question was whether to adopt Hawaiian-language names for endemic Hawaiian birds. The spelling of those names with generally unfamiliar accent marks made this an even closer call. In the end the committee decided to follow such authorities as the New York Times Atlas of the World (for country names that are included in a species name), AOU Checklist (7th ed.), and others, and to use anglicized versions of Hawaiian bird names and other established non-English names.

4. ESTABLISHED NAMES: Existing usage would be a predominant guideline.

A long-established name would not be changed just to correct a perceived inaccuracy or misdescription. “Inaccurate” names like Philadelphia Vireo and Dartford Warbler would stand. Names utilizing widespread words like Warbler and Robin for many groups of unrelated species generally would not be changed. Names with faulty descriptions of taxa were subject to change if the taxa had had several names, or if the name or the taxon was not widely known (as is notably the case for a number of tropical taxa). On occasion it was hard to draw the line between the importance of retaining a long-used name and the need to correct a misdescription, and some subcommittees drew the line more strictly than others.Throughout, the committee adopted conservative views on changing names. Various committee members from time to time suggested more radical changes in bird names. One interesting suggestion was to scrap most of the current names for taxa in the bird-of-paradise family in favor of new, more attractive, and more interesting names, like those of hummingbirds, for example. The committee could not find substantial approval of changes like these. But many of the ideas so far expressed are good ones and are at least worthy of further consideration. These should commend themselves to bird-name committees of the future.In the end most of the difficult decisions were the result of great teamwork and compromises by the subcommittees. We decided some by executive decision, playing Solomon and striving to balance wins and losses of preferred names. Radical name changes, however, are few.

5. LOCAL NAMES: Local vernacular names would not prevail over established formal names.

The committee rejected the many “local” names for species of waterfowl and the names used by native Jamaicans to describe some of their birds (e.g., Old Man Bird). If a local nickname or vernacular name had been long used as the chief or only name for a taxon, however, the committee retained it (e.g., Go-away-bird, Morepork, Jacky Winter).

6. OFFENSIVE NAMES: If a name was offensive to a substantial group of people, it would be changed.

Kaffir Rail was an example, as were names using the former name of a certain country or region, such as Ceylon (now Sri Lanka) or Formosa (now Taiwan). The name of a former country was not changed just to reflect a new name if no one was offended by the old name or there was uncertainty about acceptance of the new name, such as Burma instead of Myanmar.

7. PATRONYMS: There would be no bias for or against patronyms.

Many bird names include the names of persons, often discoverers or eminent ornithologists. Using patronyms in bird names has been popular or unpopular over the years, depending on the tastes or principles of the namers. The committee adopted a neutral stance. This had the effect of letting long usage largely govern these names, although the differing tastes and attitudes of the various committee members have played a role.

8. BREVITY AND SIMPLICITY: Each name should be as short as possible and with rare exceptions never exceed four words, hyphenated or not.

A bird’s name may consist of a single word (e.g., Brolga, Killdeer, Twite). The committee rejected the contrary view that every name must have a modifier. Yet it agreed that a taxon could have a two-word name even where it is the only taxon in its group and could therefore potentially have a one-word name (e.g., Kinglet Calyptura, Marvelous Spatuletail). Despite such rare exceptions, we adopted the general principle that brevity and simplicity are virtues.

9. ISLAND NAMES: Use of the word “island” will be limited.

If a name includes an island or islands, the word island or islands will not be included except where the resulting name is misleading (e.g., Pitt Shag and Christmas Frigatebird, but Inaccessible Island Rail).

10. GROUP NAMES: This is the most complicated issue governed by three guidelines.

The same group name may be applied to two or more unrelated groups (e.g., Warbler [Parulidae, Sylviidae] and Robin [Turdidae, Petroicidae, Erithacus]).A group name can consist of one, two, or more words (e.g., Warbler, Eagle-Owl, Green Pigeon). A single genus may have two or more group names within it (e.g., Duck, Wigeon, Shoveler, and Teal within Anas ).  Despite the great temptation to do so, we chose not to standardize group names within genera, for example, to name all species of Columba “pigeons” or all species of Turdus “thrushes.”