adding companies to a building

In a case where a building hosts many companies/departments - could someone please confirm that it is OK for me to add a node for each one, placing it within the building 'polygon/boundary' and setting the name= tag to be the name of the company/department/organisation?

Also with Potlatch2 do I do this by choosing any node type and then changing the tags for that node to be, in my case, unknown - or would I be better to put it as amenity=university?

I can't see an option to add an unclassified node type. in Potlatch2.

thanks

Sam