I am having trouble with "Entering Created Waypoints on the Route or Route Legs Pages" as described in the FCOM Supplementary Procedures SP.11.9. I want to enter an "along-track displacement" (for example, SEA/-10) so that I can then enter an ATC Speed/Level-By restriction adjacent to this point. However, whenever I upload something in this format (from the scratchpad) to the corresponding waypoint in the LEGS page (using the appropriate left LSK) I get CDU error "INVALID ENTRY". For example. On route towards MID VOR I want to create an ATC climb restriction; "Climb FL370, to be FL310 or above 60DME before MID". So I upload MID/-60 using the LSK next to MID on the LEGS page. The result is "INVALID ENTRY" in the scratchpad area. Not a very interesting topic, but it's frustrating the hell out of me!!! Any ideas greatfully received.

Are you pressing the correct LSK? One option is that you are attempting to put that restriction after MID instead of before and this is confusing the systemChris

Line select MID to the scratchpad, then add /-60 and press the left LSK next to MID.

Wow! Thanks both. Trisager's suggestion works a treat. Many thanks for the quick response. I am a happy simmer again!