Yes, it's common on the "E" lines on the GEML east of Stratford where the signal spacing is very tight. If it all comes to a halt it's not uncommon to see what looks suspiciously like a traffic jam with trains nose to tail. We also have a signal like this on the 'Up' at Broxbourne where the normal sequence will be G YY YY Y R if the platform starter is at danger, again because of signal spacing and sighting issues. However, no this is not the normal signalling sequence for 4 aspect signalling as described in the Rule Book. "Double-blocking" is another topic altogether.
There's not much point adding to what has already been said in response to the original question as posed. I think it's already been covered.
O L Leigh