Luckily for all of us, the US Copyright Office has a handy priority list for what is a best edition for copyright purposes. In fact, they even have a legal definition of best edition embedded into US law. "The ‘best edition’ of a work is the edition, published in the United States
at any time before the date of deposit, that the Library of Congress determines
to be most suitable for its purposes."
The US Copyright Office thus defines best edition of a copyrighted work to be:
- Printed Textual Media (Hardcover over Softcover)
- Motion Picture (Film over video tapes)
- Other Graphic Matter
- Phono records
- Musical compositions
- Machine readable copies (i.e., Electronic media)
- Electronic works only available online
- Works existing in more than one medium
So, why is this important for an independent or self-publisher? If you register a copyright, the US Copyright Office will demand that you register the "best edition". If you offer your book on CreateSpace, Lightning Source, Lulu, etc. before the registration of copyright is filed and processed (takes months), then expect an email or letter stating that they cannot process your request until they receive 2 copies of the "best edition", which in this case is the hardbound or softbound edition, in that order of preference, respectively.
Something to keep in mind...