http://www.caa.co.uk/docs/33/CAP413.pdf
CAP413 is the UK RTF Manual. Phraseology for conditional line up clearances can be found in Chapter 4 para 7.5. I mentioned the reason for not using the word "behind" in my earler post - sooner or later a pilot is going to take the instruction literally.
UK ATCOs are not impressed with some of the phraseology that comes from ICAO, and we have refused to use some of it recently. Examples are "stand by" on a frequency instead of "monitor," and "taxy to holding position" instead of "holding point." The number of aircraft that misunderstood the last ICAO imposed phrase and actually held position (!) caused us huge problems at Heathrow. I am all for standardisation, but only when there is no chance of any instructions being misinterpreted, especially by non-native English speakers. The ICAO way is not always the best way! Ask the Americans!