Doc-creation is not the same as the date a book was originally published: For example, A Tale of Two Cities by Charles Dickens was first published in 1854.
I am in the process of finding ISBNS to add to the books I have. Most of them do not have correct meta data.. I only want to enter the information once into the opf file....
Here is an example from Feedbooks:
http://www.feedbooks.com/item/1308700/a … -episode-1
It's actually a great example of how it can be entered badly and not follow the suggested standards.
I believe all of the free recent books from feedbooks should have ISBNs. This is probably my main source of books along with Gutenberg. Gutenberg do not put ISBN in their files.
This is the standard I used for coding my metadata in the .opf file: http://www.idpf.org/epub/20/spec/OPF_2.0.1_draft.htm
To understand the Calibre fields it would probably be best to look at Calibre itself. The Calibre fields I mentioned are generated from entering details into the fields called "Series" and "Number" on it's Edit Metadata screen. I wouldn't expect to see these field in any "fresh" epub from the internet. More publishers seem to just ignore metadata, or mess it up hopelessly.
I'm hoping with tools like Calibre, Sigil and Scarabee, users can start a movement towards better metadata.
(Calibre is very good, but it has an inflexible storage system of insisting "firstname, lastname-title" folders. I don't see much point in keeping all the Tony's together... (I'd much rather books by people that share a last name one another - Anne Mccaffrey and her son for example)
My dream machine would be to just point Scarabee at it and get it all nicely renamed (and refoldered) back to the way I want it. Right now I'm doing that all manually which takes up way too much time.