Feature summary (what you would like to be able to do and where):

Transclude a range of pages proofread in reverse order, by specifying a negative step value in a <PAGES> tag where from and to parameters behave as currently.

or

Transclude a ranage of pages in reverse order , by specfiying a to page less than the from page.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):

https://en.wikisource.org/w/index.php?title=Index:%D8%A7%D9%84%D9%85%D8%AE%D8%AA%D8%B5%D8%B1_%D9%81%D9%8A_%D8%AD%D8%B3%D8%A7%D8%A8_%D8%A7%D9%84%D8%AC%D8%A8%D8%B1_%D9%88%D8%A7%D9%84%D9%85%D9%82%D8%A7%D8%A8%D9%84%D8%A9.pdf contains a series of pages which are in a reversed order.

It is not possible currently to transclude a range of pages from a work like this as the current Proofread Page extension, will utilise an increasing page number for English language works.

Whilst it is possible for a patched scan to be created as a work-around, this requires off-wiki effort by contributors.

Benefits (why should this be implemented?):

Ability to support a greater range of works, where given sections are in a reversed order to normal.

Would also make it easier to transclude works whose page ordering is different from the normal conventions for the primary language of the work, (The thinking here is multi page Hebrew and Arabic portions in otherwise English works, but there may be others.)