Hello again,
I don't like to talk too long or too much about it.
Actually, it is not only vacancy_category_id. We can see codes like
Code:
Only registered members can view the code.
or
Code:
Only registered members can view the code.
in this file or maybe we can find similiar codes in other files.
The point is; when you start to write such these codes, it is enjoyable at first, but you won't be able to control it anymore,
and it is not predictable.
All thing that, i like to say is; they should be define in admin panel as parameters.