Originally Posted by Diegnum
We know it is "technically" correct, according to IDPF's standard.
You already know the answer, then
--- No serious (= professional and paid) product should impose arbitrary constraints.
BTW, I take the liberty of pointing you to my exlibris script: https://www.mobileread.com/forums/sho...d.php?t=180065
which might suit your needs.
( free software, both as in 'freedom' and as in 'free beer'