If I use for example the command \cite[X.2]{book} with X.2 as optional argument, I get [p. X.2,BOOK] as a result (where BOOK stands for the reference number of the book reference). Because X.2 stands for a chapter, rather then page number, I would of course like to get rid of the "p.". Because I rather rarely refer to pages, I would like to have this behaviour by default. I can probably change it using an optional argument of \usepackage{biblatex}. Which one?
Now I have in my preamble:
\usepackage[doi=false,url=false,isbn=false,sorting=none,style=numeric-comp,backref=true]{biblatex}

\pnoand\ppnoto force page numbers if need be. – moewe Mar 30 '15 at 17:02