Associate of the Royal Society of Painters and Etchers (ARPE) . Founded in 1880 as Society of Painter- Etchers and later enlarged to include Engravers, the RPE was granted a Royal title in 1888. The RPE includes various kinds of artist prints in its exhibitions and elects artists working in any of the various printmaking media.
Found on http://www.redraggallery.co.uk/art-glossary.html