Hi Vicky,
What you're probably looking is the rightsMD element.
It seems it behave in a similar way as other elements from the <amdSec>.
Here is an example by the LoC (search for ID="ADM9"). You will probably need to build something like :

<mets:rightsMD ID="ADM9">
    <mets:mdWrap MDTYPE="OTHER" OTHERMDTYPE="METSRights">
        <mets:xmlData>
            <rts:RightsDeclarationMD RIGHTSCATEGORY="Creative Commons">
                <rts:RightsDeclaration>
                    
                </rts:RightsDeclaration>
                <rts:RightsHolder>
                    <rts:RightsHolderName>National Library of Wales</rts:RightsHolderName>
                </rts:RightsHolder>
            </rts:RightsDeclarationMD>
        </mets:xmlData>
    </mets:mdWrap>
</mets:rightsMD>

If you need help converting your documents, my companies may be able to help. See contact at the end of the

--
Cordialement,
Édouard Lopez

AJLSM
17 rue Vital carles
France - 33000 Bordeaux
tél. : +33 (0)5 57 14 25 25
tél. (poste) : 05.57.14.25.22

On Thu 20 Sep 2012 12:24:39 PM CEST, Vicky Phillips wrote:

Dear All,

We are currently in the process of moving towards using Creative Commons
licences for our digitial images. I am therefore looking at how to
incorporate this within our METS documents. Has anybody else done this and
is willing to share examples? Any guidance would be very much appreciated.

Regards,
Vicky Phillips
National Library of Wales

Cordialement,
Édouard Lopez

AJLSM
17 rue Vital carles
FR - 33000 Bordeaux
tél. : +33 (0)5 57 14 25 25
tél. (poste) : 05.57.14.25.22