1) Commonly named 2) Designated as such 3) Falsely designated 4) Inaccurately designated 5) Incorrectly-named 6) Known inaccurately as 7) Of questionable repute 8) Popularly termed 9) Self-styled 10) Supposed, doubtful 11) Termed as such 12) Titled, perhaps undeservedly Found on https://www.crosswordclues.com/clue/so-called
So'-called` adjective So named; called by such a name (but perhaps called thus with doubtful propriety). Found on http://www.encyclo.co.uk/webster/S/136