Last one, and it's bugging me!
1dn Separate leaves to put in a box? (4)
C _ F _
Coff has connotations with coffin, so I'm leaning towards that, but I don't get it - unless it has a reference to COFF, which is some computer system I couldn't begin to understand the explanation of on Wikipedia.
The Common Object File Format (COFF) is a specification of a format for executable, object code, and shared library computer files used on Unix systems.
Thanks for suggestions!
The explanation of COFF still makes no sense to me - I'm a Luddite!
No - no computer theme to xword, but thanks for F = folio idea.