Colloquial names?

Hi

What is the policy of using colloquial names?

There’s an area of my home town that is known locally a Bog island. (it used to have a public toilet).
This is not the official name for it. I’m not even sure it has one.

However the local newsagent renamed itself Bog Island news, so the term is definitely widely used
In fact to such an extent that last year I had a tourist asking me directions there.

Should I tag it’s name as such?

Cheers
Dave F.

I’d suggest to use loc_name (http://wiki.openstreetmap.org/wiki/Map_Features#Name)

Thanks