SR Flip-Flop: NOR or NAND?
Both are SR latches. 

The SR NOR latch will have the following truth table:

----------
S  R   Q
----------
0  0   no change
0  1   0
1  0   1
1  1   not allowed
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SR NAND latch is an inverted version of SR NOR latch. The truth table of which is:

----------
S  R   Q
----------
0  0   not allowed
0  1   1
1  0   0
1  1   no change
----------