Suppose 2 different marks are being filed by the same organization, at roughly the same time, for the same fundamental service with the USPTO. Such as Microsoft filing for Windows and Rectangles, both marks later being used for a single operating system. Maybe they will eventually consolidate on one mark over the other but for now, both marks will be used in commerce. The organization wishes to file identical "proof of use" evidence except that the mark is different on each. Must the "proof of use" demonstrate somehow, through other details within the "proof of use" evidence (e.g. service characteristics) that mark #1 is somehow different than mark #2? Or, in other words, could the examiner refuse mark #2 and, if so, on what grounds? Arguably, the organization in this example could try to make each distinguishing but it would require more work and be more odd in commerce.