Dado layouts

[Donald Thomson]

Attached is a nesting diagram of a part I need to cut for a project. Since flip operations are sketchy at best for me, I need to route the dados (in green) with a router. The layout gives dimensions of where those dados are supposed to be positioned.

My question, The "From Left" column gives how far the dados are supposed to be from the left end. Is that dimension from the left end of the part or is it from the tenon shoulder?

Thank you!