Admin variable identifier is [ad]
It is the first chapter but actually, administrative variables are quite easy to use.
There is a few logical branching here. If you want to create a country-level variable, you will need to gather back several subvariables including
reporting_region, (USA are a stand alone in this variable)
australia_countries. These variables are mutually exclusive (except for reporting_region).
Useful when you want to draw the world map of contributing countries.
Please look at the contributors and contributing centers section for more details.