  An automated treatment of iterated integrals based on letters induced by
real-valued quadratic forms and Kummer--Poincar\'e letters is presented. These
quantities emerge in analytic single and multi--scale Feynman diagram
calculations. To compactify representations, one wishes to apply general
properties of these quantities in computer-algebraic implementations. We
provide the reduction to basis representations, expansions, analytic
continuation and numerical evaluation of these quantities.
