Do I use /es/, /mx/ or /es-mx/ for my Spanish site for Mexico only

[RoxBrock]

I currently have the Spanish version of my site under myurl.com/es/

When I was at Pubcon in Vegas last year a panel reviewed my site and said the Spanish version should be in /mx/ rather than /es/ since es is for Spain only and my site is for Mexico only.

Today while trying to find information on the web I found /es-mx/ as a possibility.

I am changing my site and was planning to change to /mx/ but want confirmation on the correct way to do this.

Does anyone have a link to Google documentation that will tell me for sure what to use here? The documentation I read led me to the /es/ but I cannot find that now.

[RoxBrock]

Thanks much!

[Philip-DiPatrizio]

Here's the Google documentation on multilingual and multi-regional websites: https://support.google.com/webmasters/answer/182192?hl=en

You will also want to read up on hreflang here: https://support.google.com/webmasters/answer/189077?hl=en

I would personally go with example.com/mx