Minecraft wiki entry for Memory, associated text: Expand an RS latch easily into a monostable circuit, which automatically disables itself some time after activation. To do this, split the output redstone path into two parts. The new path should run through some repeaters, and in to the reset input. When players turn on the latch, redstone feeds a signal through the delay before turning off the latch. This works not only for Q and R, but for Q̅ and S as well. A more complex delay mechanism, such as a water clock, can replace the repeaters.
An "Enable/Disable RS latch" can be made by adding a pair of AND gates in front of the inputs, testing each of them against a third input, E. Now if E is true, the memory cell works as normal. If E is false, the memory cell will not change state. That is, E latches (or equivalently, clocks) the RS latch itself. Note that for design Q, the outputs are not isolated, and a signal to them can set the latch regardless of E. Alternatively, repeaters could be used to latch the inputs, but this costs more and saves no space.
As noted above, if it is possible to add a "toggle" input, the RS latch becomes an RST latch. If the "forbidden" state is used for the toggle, then it's a JK latch.