Blurb "cover" command doesn't make sense

As I’m building up, I came across a discrepancy in how the Frontispiece chunk is supposed to work. According to version 2.0.4 of the Blorb specification, the ‘Fspc’ chunk contains the resource number of a ‘Pict’ chunk. According to Graham’s cBlorb manual, this chunk is restricted to containing “1”. This doesn’t make good sense from a grammar perspective.

To clarify… I’m trying to work out the correct way of implementing the “cover” command in the Blurb language. The way I read the Blorb Specification, the Fspc chunk indicates which Pict resource is the cover or the “frontispiece”. This implies that the value of the Fspc chunk could be any positive integer up to 2^64.

Any unsigned nonzero integer up to 2^32, yeah. Sounds like cBlorb doesn’t give you the flexibility that’s permitted. (I haven’t looked at the manual.)

Whoops! yah. 32 bits, not 64. Anyhow, here is the relevant passage from cBlorb’s manual (page 7):

I decided to implement the cover command as being equivalent to picture cover "logo.png" with an Fspc chunk being added. I understand this may cause incompatibility between pblorb and cblorb, but given that pblorb is mainly for Inform6 use, I figure this is acceptable. I’ll continue porting as much of cblorb’s functionality that I can back to pblorb. I’ve kept some of the more exotic functionality so that one can always rebuild blorbs for the Infocom titles that use audio or V6. I’ll probably soon come up with some more programs to automate Treaty of Babel stuff for Inform6 users.