Jars, good interesting idea, and it is a new suggestion as far as I know. For a workaround method in the meantime (granted this is less convenient) you could label the top row of square grid on your own with the type tool (A, B, C, D, E...) and then number the left-column of the grid (01, 02, 03, 04...), this would give you coordinates that the players could name (move me to square C-02). Another possibility is using the API to number the squares or to create the coordinates; the API is a perk for Pro subscribers. I don't know of an API script currently existing for this request, but if you subscribe as Pro then you can ask in the API sub-forum and my impression is this API would be possible to create. Note your suggestion is still valid for a Suggestion to add into Roll20, these are just some ideas to help for now.