I design electrical control circuits using Computer-Aided Design software for some fairly complex machines, and some that are similar but not so complex, all on A4 size pages.
When i need to do a new simpler version i take a complex version, delete the bits that are not needed and use that as a 'base' for the new design. This usually leaves pages in the drawing set with no content.
For very time consuming reasons i don't take those out and renumber the other pages in order, i simply mark them as 'spare' and leave them in.