NY Times article (reg. req.) on American Apparel, which is “Building a Brand by Not Being a Brand,” if you go in for that reverse psychology kind of thing. There ‘is not a logo in sight’ in its 26 stores.
The PTO online database indicates that its application for AMERICAN APPAREL has been approved for publication after the applicant submitted evidence of secondary meaning (the mark has been in use since 1988 – the company also owns prior registrations for ALL AMERICAN APPAREL).
MUJI is a Japanese retailer that also adopts ‘no branding’ branding.