Public landlord usually means that the property is owned by a government authority:
https://en.wikipedia.org/wiki/Public_housing
https://www.bing.com/search?q=public+landlord&aqs=edge..69i57&FORM=ANCMS9&PC=U531
https://en.wikipedia.org/wiki/Public_housing
https://www.bing.com/search?q=public+landlord&aqs=edge..69i57&FORM=ANCMS9&PC=U531