Presumably they mean a printed on the mass market shelves book.
Well firstly, all my writing I class as real books. But as far as the books we see on the shelves here goes.
I'm almost finished a Romantic Suspense targeted at Harlequin and probably also designed with the possibility of getting me an agent. If this book doesn't interest agents I'll keep writing until on does. I'm also waiting to hear back on a Spice Briefs sub from Harlequin. Maybe I'll get in there and get the opportunity to write a full length Spice for them one day.
Harlequin guidelines here
I'll also be subbing for the Kensington Brava contest 750 wd comp for a Novella length work.
I'll keep you all posted on subs as they go in