On the left side of
in, there is always a single value. The list of options, which could be a taxonomy, goes on the right side of
e is Entity
e.domicile not in EUCountries
There is one answer for what the domicile of an entity is, so this is a single value. With the conditions in the example, you check whether this value is not a part of the taxonomy
EUCountries, which predictably consists of a list of all the member states of the European Union.
e.domicileis in the United Kingdom, the condition evaluates to true. The document will be included in the case. If
e.domicileis Belgium, the condition evaluates to false, meaning the document is excluded.