Is it appropriate to register a girlfriend with "companion registration" for an academic conference? Maybe my question is rather weird, but actually it turned out it is also a question of my colleagues. 
Usually when you register for an academic conference, there's an  option that you can register a companion. I'm wondering if it is appropriate to register my girlfriend as a companion? Does it sound so bad?
In the conferences I am aware of, companions are people not attending the conference, but coming along with some of the participants for tourism or company. Depending on the venue, they may or may not offer some alternative activities for them (anything from visits to the city to a heap of maps and sort yourself out).

If this is the case, your girlfriend would fit right in, as long as she is not interested in the conference itself.