[KevinH]

Edit:

The opf does in fact use a *hardcoded* empty opf template. See Sigil/src/ResourceObjects/OPFResource.cpp

Its would need to be changed in 2 places: TEMPLATE_TEXT (starting near line 63 for epub2) and TEMPLATE3_TEXT (starting near line 107 for epub3).

If you know the xml metadata code for what you want (and it differs between epub2 and epub3 for Author metadata), you could hard code it here.

But wouldn't be easier to create an empty epub of each type and use the MetaData editor to set what you want and do a file save-as under a new name once. Then load that special empty epub anytime you want to start creating an epub (always using file-save the first time to a new name).

And I still have no idea what you could possibly store in any dc:description metadata that would be meaningful across different epubs? And Author is reserved for the creator of the book text not the person who creates the epub, so that would differ as well across your book collection.

Better yet ... why not just use Calibre and its ebook Library metadata capabilities to set all of this.