Yale University The Application-Layer Traffic Optimization (ALTO) Service has defined both the endpoint cost service (ECS) and cost maps to provide information to applications about network path properties (e.g., routingcost) from a set of source network points to a set of destination network points, where each network point can be a single endpoint (in ECS) or a PID which represents a set of endpoints (in a cost map). Considering, conceptually, both ECS and cost map as returning a matrix, indexed by sources and destinations as row and column, the current ALTO protocol [RFC7285] allows the elements in the matrix to be only scalar (i.e., numerical or ordinal). This, however, is limiting in many use cases. This document discuss multiple use cases where scalar-elements can be limitations. It then defines new cost types to allow general cost types, such as vectors to represent use cases such path vectors.