Thanks for the mention of BNF! I've been learning everything myself as I come across stuff -- I learn in my spare time, this isn't part of my curriculum,
yet -- so I appreciate any time someone mentions anything I haven't come across yet. (I was wondering a bit what some description were that turns out to be BNF.)
According to Kovid's docs (and thus my understanding),
Code:
{authors:uppercase()|prefix|suffix}
is valid but the way you describe it, it must be
Code:
{authors:uppercase():|prefix|suffix}
Is this optional, or did you/kovid make a mistake?
I'd test it out myself but I typed this on my Kindle Touch.