If you come across an XL Series card that has a number with a 'R', 'V' or 'A' then there is almost certainly another version of it out there with a different caption. This is quite useful so you can keep an eye out for the variant.
However, I recently came across an example which doesn't have any of these extra letters appended to the number. The following two cards are both published as XL Series No. 2165: