Can one add items to a list within(!) the inventory?

Hi,

is it possible to expand a list variable within the inventory? E.g. I have a list of users which should be allowed on all hosts but on /some/ hosts, additional users should be allowed. I want to define this in the inventory:

So far I so:

Yes and no, variables cannot 'self reference' so they cannot all be
named `users`. Even then, not in the ini file format, you need to
either use a YAML inventory or YAML group_vars/host_vars