Yes, you can create Reverb Sites exclusive listings for brands that restrict you from selling on Reverb but allow you to sell through your own website.
When creating a listing from scratch on the sell form, scroll to 'Advanced Options' and expand to see the additional fields.
Locate the 'Exclusive Sales Channel' section.
Click the dropdown menu to view the options, 'All Channels', 'Reverb Sites', or 'Reverb'.
Save your changes at the bottom of the page after filling in all the details of your listing.
This can be updated or changed at any time by following the same process.