Parameter Value: [yourcode]
BrandingCode is used to white-label Conga Composer for Enterprise Edition customers. After submitting your logo to Conga you will be provided with a Branding Code to be entered with this parameter.
Contact your Account Manager for more information about Conga Composer Enterprise Edition.
If you want to add a Branding code to your Salesforce org, log a support case and provide the publicly accessible image URL.