SL/SR are either side of the the listening position (or to the side and slightly behind for 5.1), SBL/SBR are behind. SL/SR are the same for 5.1/6.1/7.1, the additional terminals are only used for 6.1/7.1.
No problem - it's easy to see where the confusion lies.
In a 5.1 set up, the rears should really be between 90 degrees (i.e exactly at the side of the listening position) and 120 degrees (still to the side, but further back, 180 degress being exactly behind the listening position). However, most diagrams will show the positions in the rearmost possible position (or even further back in some I've seen).
When 7.1 is depicted, the original rears are pushed forward (to 90 degrees) and the additional speakers inserted behind and between the originals. However, it can easily look as if the original rears have moved closer together and the additional speakers added to the side.