ATX screw placement question

[Adrenaline]

My motherboard tray calls for a 10th screw holder but there is only 9 places for screws to go in. I have never used one there in the past and have always wondered if this was "needed".

http://www.formfactors.org/developer%5Cspecs\atx2_1.pdf

Page 10 the B slot position.

 

[fffblackmage]

You're probably fine without it. I'm guessing it's just added support for mobos with SLI or xfire.

 

[Adrenaline]

Thanks.

 

[Aluvus]

From page 9 of that very same document:

The hole at B in Figure 2 was previously required along the rear edge of the board. This location is not required for ATX designs. If it is desired to implement a board mount in this area, a removable standoff should be used to avoid problems with boards that do not use this mounting location.

microATX does require it. Most ATX motherboards don't use it, and as long as they use holes A and C (which every ATX board I've ever seen does) it shouldn't matter. It has nothing to do with (and greatly predates) SLI or Crossfire.