Hi @planktonwebdesign
yes, this is possible, however it is not part of the core plugin.
You will need to create a new location rule which will take about 10 mins to do.
With this new location rule, you can look at the current logged in user and compare the username to ‘jeff’. If a match is found, return true, otherwise, return false.
http://www.advancedcustomfields.com/resources/tutorials/custom-location-rules/
Thanks
E