If required the additional information listed below should be included in your Mechanical Layer data.
The distance from one drill hole in X and Y to the PCB outline.
This is particularly important when you only have NPTH holes without copper pads.
Drill Position Symbols
Positional indication of all drills using symbols (=drill map).
Use different symbols for each different drill size.
Indicate which holes and slots are PTH and which are NPTH.
If you supply panelised data include proper indications for break-routing and/or scoring (V-cut).
A clear layer sequence or buildup drawing for all copper, soldermask and legend layers.
Include any additional layers such as peel-off or carbon.
Provide the correct sequence as viewed from top to bottom and with the correct corresponding data file names.