What happens when the number 1 is a B737 and so is the number 2,3,4 and 5.
"After the Landing B737 line up and wait"
I think that in the ICAO docs Roger means "received and understood".
To me that simply means that;
1. The message has been received in full
2. The message makes sense
The actions or not subsequent to receiving the message may not be the responsibility of the person receiving the message and it may take some time for the person receiving the message to inform the responsible person of the message. I am not just talking about radio operator passing message to pilot it could be PNF receiving the message and interupting the PIC's dinner to pass on the message.