ABSTRACT
Let (P1, . . . Pn) be an element of (RP 2)n with n ≥ 5, treated as a configuration of n points in one single real projective plane. The (combinatorial) ordered Lconfiguration of (P1, . . . Pn) is the combinatorial data describing the mutual positions of each point with respect to the set of lines through any two others, and the (combinatorial) ordered Q-configuration is the data describing the mutual positions of each point with respect to the lines through two others and the conics through five others (L stands for linear , Q for quadratic). These data will be described with some encodings involving the indices 1, . . . n.
