- Publisher - The name of the book's publisher. Use the official statement of publication where you can. The publisher has in the past not been a key entity in the ISFDB, but publisher and imprint support is in the process of being improved, and a process of determining canonical names for publishers and imprints is in progress. For the time being you are free to choose an imprint ("Ace Books"), a division ("Berkley") or the parent corporation ("Penguin Group (USA)") as you wish. Imprints are often a suitable choice since they may be genre specific. A good rule of thumb is to choose a publisher name that would not surprise the reader; thus "Del Rey Books" is a better choice for that imprint than "Ballantine Books", even though Del Rey was in fact an imprint of Ballantine, because Del Rey's imprint is the prominent label on the cover of those books, whereas "Ballantine" appears only in small print at best. However, if both an imprint and a publisher are listed, and particularly if both are known for publishing genre fiction, consider listing both. For example "Del Rey / Ballantine" may be an even better choice than either "Del Rey Books" or "Ballantine Books".
- For self-published works, fanzines, bibliographic pamphlets and the like, use the name of the editor/author if no other publisher information is visible. Sometimes a fan organization or something similar will be quoted as the publisher, e.g. for books or booklets issued as sf convention special publications: these are not strictly publishers, but should be treated as such for this field.
- Where multiple forms of a name exist, it is not important to always enter exactly the form of the name as it appears on the book. For example, an imprint may say "A Tor Book", "Tor", "Tor Books", "Tor Books Science Fiction", or "Tor: A Tom Doherty Associates Book". Sometimes several of these varying forms will be on a single book. These can be converted to a canonical form; in this case "Tor" would be the sensible choice. The ISFDB does not currently have a page to identify and document canonical forms for publishers but may do so in the future.
- Case should be regularized unless there is a clear reason not to. For example, a Tor book often gives the imprint name as "TOR Books"; this should be entered as "Tor Books". DAW, however, is an acronym, and so "DAW Books" is the correct form for that imprint. Publishers of magazines are often printed in uppercase -- e.g. Fantastic Universe's statement of printing shows "KING-SIZE PUBLICATIONS, INC." as the publisher; the form "King-Size Publications, Inc." should be used here.
- If you are entering both the imprint and publisher name, as in "Del Rey / Ballantine", then it should be entered as Imprint / Publisher with the imprint first, spaces around the slash, followed by the publisher name. Note, it's still ok to enter things like "Imprint, an imprint of Publisher". The things we want to avoid are the Imprint/Publisher (with no space) and Publisher / Imprint (imprint / publisher flipped around) and formats.
- Library records, and in some cases the copyright pages of books, often list publishers with a preceding city, as "London: Mammoth Books Ltd" or "New York: Giant Press inc". In such cases, list only the actual name of the publisher, not the city. (Existing records should not be changed to match this standard without considering how to avoid data loss). The city or country can be listed in the notes field of the publisher record, or on an associated wiki page, or both. Where needed to avoid confusion, a country suffix may be used, so we might have, for example, "Mammoth Books (UK)" and "Mammoth Books (Canada)".
- Science Fiction Book Club books should be entered as "Publisher / SFBC" where Publisher is the publisher name stated on the publication. Also see How to enter a SFBC publication.