very interesting - thanks for posting that link. I get the impression that marks included in this link were those used on ceramics only, but there's no getting away from the fact that the post 1998 mark shown appears identical to the o.ps. image, which looks to be on a piece of glass. It seems remarkable that no one here recognized this backstamp as being from Wedgwood - especially as Rosie pointed out that part of the mark included the Portland Vase.
My opinion would be that the o.ps. image does agree with the backstamp in the link, from Wedgwood, and it's either scarce - added to ceramics usually and not often perhaps glass - perhaps confined to certain types of object.