By default, everyone can buy from everyone. There could be cases, however, where a seller might want to deny service to a certain BrickLink member. The seller has the option to Stop List any member.
BrickLink neither supports nor denies a seller's decision to stoplist someone.
Stop List Reason:
When you stop list a member, you may also optionally enter a reason why you are putting that member on your stop list. The reason is only viewable by you and not displayed to the member stoplisted.
Item Exclusion (for the buyer):
You can select to hide items from stores that stoplisted you in searches and wanted list results on the following pages: