Well known or Well-known is a phrase use in several technical contexts: ...
• (a.) Fully known; generally known or acknowledged.
Well'-known` adjective Fully known; generally known or acknowledged. « A church well known with a well-known rite.» M. Arnold. 
adjective widely or fully known; `a well-known politician`; `well-known facts`; `a politician who is well known`; `these facts are well known`