Quote: In OZ........ ROGER is used to signify "message understood"
Thats interesting because in the UK "Roger" simply means that you have received ALL of the last transmission. It has nothing to do with comprehension, agreement or complying. In other words you may not have understood any of it, but the reply is still "Roger". This is obviously an extreme example, but nevertherless correct.
However, only a fool would not then ask questions to clarify any uncertainty.
In the UK, "yes" is spoken as "affirm" and "true, or accurate" is spoken as "correct" on the RT.
All in CAP 413