I only know of two definitions of Aves which satisfy PhyloCode rules:
- Gauthier and de Queiroz, 2001: "The crown clade stemming from the
most recent common ancestor of Ratitae (Struthio camelus Linnaeus
1758), Tinamidae (Tetrao [Tinamus] major Gmelin 1789), and Neognathae
(Vultur gryphus Linnaeus 1758)."
- Sereno 2005: "The least inclusive clade containing Archaeopteryx
lithographica Meyer 1861 and Passer domesticus (Linnaeus 1758)."
There has been some discussion recently on the ISPN's forum:
http://www.phylonames.org/forum/viewtopic.php?t=7
(The ISPN is the organization associated with the PhyloCode: the
International Society for Phylogenetic Nomenclature.)