Adding Extranet Account Manager

When adding a Extranet Account Manager using powershell (Add-ExCMExtranetAccountManager), what do you mean with the Identity of the Extranet Service. -Service Add-ExCMExtranetAccountManager -Identity -MembershipProviderName -Service

The identity is the claims login name of the user you would like to make an account manager. The format of a windows account would look like 'i:0#.w|domain\accountname' and a forms account would look like 'i:0#.f|membershipprovider|accountname'. You can so us the shorthand login name as shown in the hep document below...

(Add-ExCMExtranetAccountManager)
http://help.sharepointsolutions.com/products/excm/Troubleshooting_InvalidResource.html