High Quality Content by WIKIPEDIA articles! The Society of Architects was formed in 1884 and continued until 1925. At that time Fellows and Associates comprised two distinct classes of membership of the Royal Institute of British Architects (RIBA). They were respectively entitled to use the post-nominal affix "FRIBA" or "ARIBA". The formation of the Society of Architects was a result of a campaign by a group of Associates to be allowed to vote on the affairs of the Institute which the Fellowship class had resisted.