certmap.conf default

hello,
I have some trouble with a certmap.conf.

I don' know the behaviour when all is commented like this:

certmap default         default
#default:DNComps
#default:FilterComps    e, uid
#default:verifycert     on
#default:CmapLdapAttr   certSubjectDN

Which default is used ?
I found" If there is not a DNComps entry in the mapping, the server uses either the CmapLdapAttr setting or the entire subject DN in the client certificate to determine where to start searching."
But default:CmapLdapAttr is commented .

Tks a lot