luser question concerning invisible

Hi,

I use in the fetchmail command line --invisible when
using fetchmail with ssh port forwarding.
I tried to put invisible in the .fetchmailrc file
in the defaults: part

defaults:
        user x is user y
        inivisible
        no rewrite
        fetchall
        smtphost bla.bal

poll bla bla bla

However, i keep getting errors concerning the inivisble part
or the fetchmailrc file.
So i have to do it in the command line.
What am i doing wrong here?
Btw .. couldnt find an entry about this in the
FAQ.
Bye,

Mipam.