Document layer just for you to add some notes, we don't print them on PCB board, even no gerber output.

@dillon Thank you Dillon! You my man! :D Just wanted to be sure.

Is there are reason for this PCB check from your 'Essential checks before placing a PCB order' page?  19) Check that no board outline, silkscreen or documentation layer information has accidentally been placed on any copper layers; If the documentation layer is not part of the final design, why do we need to ensure none on copper layers?  I have copper traces running through the documentation layer information. Thanks!

"Is there are reason for this PCB check from your 'Essential checks before placing a PCB order' page?  19) Check that no board outline, silkscreen or documentation layer information has accidentally been placed on any copper layers;" Sorry but I'd have thought that was pretty self explanatory. If you have information that you intend to put in the board outline, silkscreen or documentation layers but you accidentally put it onto a copper layer then that's probably your PCB trashed because you have just shorted things together. And yes, I have seen PCBs where that has happenend. :)

But thank you for taking the time to read the checklist.