It used to be that a species name was only official if it was printed in a journal - and the print was quite literal, it had to be a print journal.

Why do zoologists hate trees?  They don't any more, it seems. Animal species publications is now allowed by a new vote of the International Code of Zoological Nomenclature (ICZN) today. The ICZN considers itself among the most rigorous in scientific publication and the task of keeping information straight on animal names is immense and critical, as almost all data on the living world is linked through organismal names. Animals comprise the vast majority of multicellular species recognized (currently around 1.8 million, growing at a rate of about 20,000 per year) and for each of these taxa, there are as many as 2-10 legitimately published names due to past debate and poor information exchange. Estimates of the total of living animal biodiversity are 4-20 times this number (8-50 million species).

That's a lot of dead trees.  But no more. ICZN has passed an amendment that considers a publication in a digital scientific journal ‘legitimate’ if meeting archiving criteria and the publication is registered at the ICZN’s official online registry, ZooBank. The Amendment was published simultaneously in the journals ZooKeys and Zootaxa.

The change in ICZN publication rules is intended to speed the process of publishing biodiversity information, to improve access to this information, and to help reduce the ‘taxonomic impediment’ that hinders cataloging of the living world. The move, however, is seen by some as a risky experiment in un-mooring a previously well-anchored system of linking publications, names and taxonomic concepts.

The ICZN ruling is explicit that while the publication can exist in an electronic-only format, it still must be published through a journal or book that has an ISSN or ISBN (International Standard Serial Number or International Standard Book Number) and should indicate that it will be archived for long term access. Purely web options such as blog posts, forums, Wikimedia, Wikipedia, Scratchpads and other potentially ephemeral, unarchived web-only sources still do not qualify as legitimate publications under the new ICZN rules.

“The change in ICZN publication rules is intended to speed the process of publishing biodiversity information, to improve access to this information, and to help reduce the ‘taxonomic impediment’ that hinders our cataloguing of the living world. The new rules will open the door to electronic publication and facilitate a truly web-based taxonomy!” said Dr Ellinor Mitchel, Executive Secretary of ICZN.

Reference: International Commission on Zoological Nomenclature (2012) Amendment of Articles 8, 9, 10, 21 and 78 of the International Code of Zoological Nomenclature to expand and refine methods of publication. ZooKeys 219: 1–10. doi: 10.3897/zookeys.219.3944