Hidden on the next motherboard slot

If you want to block three cards of one has bad cards.
The card is so thick that they equal mitbelegt over next slot, ie 3 slots required instead of 2 as indicated with 45mm.
That is the third card has no place, however, already the second, because the vast majority of motherboards between the first and second PCI-E slot 2 slots have free.

This can be guessed based on the dimensions 45mm maximum with folding rule, would be really nothing wrong with that to be noted as a bold warning somewhere.