Reply To: Reverse Numbering

Should be fairly simple, though I haven’t seen your document. Prepare your document as follows: on each master page place a text frame for the page number and name it ‘folio’ (without the quotes) on the Layers panel. Then run this script:

(function () {
  var i, index;
  var frame;
  var n = 1;
  var pages = app.documents[0].pages.everyItem().getElements();
  for (i = pages.length-1; i >= 0; i--) {
    n--;
    if (pages[i].textFrames.item('folio').isValid) {
      pages[i].textFrames.item('folio').remove();
    }
    if (pages[i].appliedMaster !== null) {
      index = pages[i].side === PageSideOptions.LEFT_HAND ? 0 : 1;
      frame = pages[i].appliedMaster.pages[index].textFrames.item('folio');
      if (frame.isValid) {
        frame = frame.duplicate (pages[i]);
        frame.contents = String(n);
      }
    }
  }
}());

When you add and/or delete pages, simply run the script again.

Peter