Changing the Tag Key

[jtwp]

What file denotes the format of the Tag "Key". I'd like to change "instance_id" and "device" to something else, but can't find the exact file or files where this is set? I have tried changing it where I can see it, but doesn't seem to make any difference.

[paulwakeford]

They are set in core.py lines 207 and 208.