Many ~ most ~ books have flyleaves. At the front of the book they are the first recto page after the cover [112703]. That is ~ the first right hand page met by the reader, as the cover is lifted. The inside of the cover is (traditionally) the endpaper[123368].
I write 'traditionally' because many recently bound books, particulary 'paperbacks', do not have, or need, end-papers and flyleaves.
Flypage is a new word to me ~ I hope I have got all this correct ~ is a spare, and unnumbered sheet inserted into the book. I use it, now, to describe the first leaf to follow the flyleaf. It can also describe
I learned what a flyleaf was way back early in my college bookbinding course, but never met the word flypage before today. I had planned to write a note about leaving a blank page near the start of a book. By that I mean the page following the flyleaf. To check that I was not writing false stuff I did a search on the WWW for 'flyleaf', which confirmed my own understanding of the word. I also stumbled across flypage, and immediately saw it as being a useful a word to have in my vocabulary. I suspect the note above introduces one ~ maybe two ~ words to the readership. As always I eagerly await corrections or suggestions [123465].