Page count.
The total number of interior pages...
 
Your page count is determined by the number of pages in your final PDF (interior text) file and must always be an even number. Cover submissions should always be in a separate file.
Saddle stitched MiniBük configurations increase in 4 page increments from 8 to 48 pages. Perfect bound MiniBük configurations increase in 2 page increments from 64 to 240 pages.