The standard appears to be this
IPC-7351C Level A = Pin 1 in Upper left
IPC-7351C Level B = Pin 1 in Lower left
That appears to be ambiguous in the case of 2 pin diodes or caps, but maybe the spec explains that. Also, I still don't know what the reference zero angle is, geometrically the convention is that zero points right, along the X axis. Also, if the manufacturer defines pins as A and K, and also shows orientation in the tape, but never defines "pin 1", which is pin 1?
I recently tried to upload a design to MacroFab, and they try to place from the Kicad PCB. They then give you the option to manually alter the orientation. That all seems very neat, but unfortunately, as they don't specify what orientation they use, nor did they respond to emails, I had no idea what to specify.