Memory flags allow you to transmit a signal from one place in the config program to another (for example across different pages, or from one place on the page to another which is useful if you have lots of criss-crossing lines starting to form!). It is essentially just a line broken up with the flags:
To insert a memory flag click on a page and then hit F5 and search for “memory”. When a memory flag is first inserted it is an output (so receives a signal). It is displayed in the Periphery tree under the Memory flags section. Also give the memory flag a sensible name so you can find them easily again (important in a large config). Then you can drag the memory flag back on to a page and it is now an input.
By default the memory flag is digital, but if you need to transmit an analogue value you need to uncheck “Use as a digital flag” in the properties.
Two memory flags are connected from the triple click output on the lighting controllers from the Lounge and Kitchen lighting pages. These are then connected to another memory flag All lights off. This is then connected to the R input on the lighting controller so that when a triple click in any room is done all the lights in the house will go off. The virtual input All Lights Off is also connected to the All lights off memory flag.