This inside of this issue is actually #5, though the cover states it's #6. The inside indicia states it is #5, and an explanation is given by the editor in the inside cover of the next issue, #6 - the white cover.
When going to press, the covers to both 5 and 6 were placed on #5, so this is a variant of #5. There is no record of ratio production so it is probably 50:50.
The white cover on #6 states on top that it is "The Real No. 6".