What are unitas?

Some articles on unitas:

Wissenschaftlicher Katholischer Studentenverein Unitas Stolzenfels Zu Bonn - Traditions - Principles and Motto
... Scientia requests every member of Unitas, to deal with other academic subjects than one’s own ... Unitas Stolzenfels is In necessariis unitas, in dubiis libertas, in omnibus caritas In necessity unanimity, in doubt liberty, but above all charity ...
Wissenschaftlicher Katholischer Studentenverein Unitas Stolzenfels Zu Bonn - Traditions - Flags and Colours
... The colours of Unitas Stolzenfels are the colours of the Unitas Verband in the order of white blue gold The flag of Unitas Stolzenfels shows the colours white-blue-gold in ... Underneath it reads „Unitas Stolzenfels sei's panier“ (Flag of Unitas Stolzenfels) ...