How to 'update' vendors when introducing a new specialisation to the system?

I'm basically looking for best practices here. From time to time there is the need to add a new specialization to our list. Of course, since it's new, no vendors in our database will have that specialization registered, even though perhaps are capable of working in that field.

What could be a good way of handling this? Should I send out surveys/update requests periodically to all vendors? How do you deal with this?