Checkout the [Strong Parameters](https://github.com/rails/strong_parameters) homepage. they have laid out a pretty standard way of naming the query methods for params. i.e. `invitation_params`.

```ruby
def invitation_params
   params.
     require(:invitation).
     permit(:invitation_text).
     merge(
       event: event, 
       invitee: find_or_create_user, 
       sender: current_user
     )
end
```