You are waiting at the end of the runway when tower says "Behind the landing Air Bus, line up and wait." In the United States you question the tower's sanity but under ICAO you are expected to acknowledge, repeating the clearance exactly, and as soon as you see the landing aircraft pass in front of you, you line up and wait. It is ICAO, to be sure, but I've only seen this done in Europe.
What follows comes from the reference shown below. It seems odd that the only place this procedure appears is in a chapter called "phraseologies." Where I think it helpful, I've added my own comments in blue.
[ICAO Doc 4444, ¶12.2.4] Conditional phrases, such as "behind landing aircraft" or "after departing aircraft", shall not be used for movements affecting the active runway(s), except when the aircraft or vehicles concerned are seen by the appropriate controller and pilot. In all cases a conditional clearance shall be given in the following order and consist of:
"SAS 941, BEHIND DC9 ON SHORT FINAL, LINE UP BEHIND".
Note.— This implies the need for the aircraft receiving the conditional clearance to identify the aircraft or vehicle causing the conditional clearance.
It may exist someplace else, but this is the only place I've seen it in writing. In actual practice, however, I've seen it several places in Europe, usually in the form "Behind the landing _____, line up and wait."
Portions of this page can be found in the book International Flight Operations, Part VIII, Chapter 13.
ICAO Doc 4444 - Air Traffic Management, Fourteenth Edition, Procedures for Air Navigation Services, International Civil Aviation Organization, 2001 *
ICAO Doc 4444 - Air Traffic Management, Fifteenth Edition, Procedures for Air Navigation Services, International Civil Aviation Organization, 2007 *
* Not all of Doc 4444 seems to have been reproduced in the 15th edition, so you might need to look at the 15th edition and then then 14th edition for some sections.
ICAO Doc 4444 - Amendment No. 1, Procedures for Air Navigation Services, International Civil Aviation Organization, Amendment No. 1, 2007
ICAO Doc 4444 - Amendment No. 2, Procedures for Air Navigation Services, International Civil Aviation Organization, Amendment No. 2, 19/11/09