It certainly isn't described in the R44 POH, which I have at home.
The wikipedia article says it is in the (2013 edition) R22\R44 Flight Training Guide (FTG), which is the fifth manual listed at
Robinson Helicopter Co.
Whilst, I can find html versions of all the POH's Robinson website (and it isn't in those), there doesn't appear to be a html version of the FTG and I don't have access to a hard copy.