it's not completely undocumented

found some definition here: Proposed_features/shops_(multiple)#shop_types. --Dieterdreist (talk) 19:22, 8 September 2016 (UTC)

I will add this definition to the article, then, since this tag has over 400 occurrences. –Virgilinojuca (talk) 16:25, 26 April 2017 (UTC)

Talk:Tag:shop=sewing