ITU-T Recommendation T.126 defines a protocol supporting the management of common multi-layer visual spaces and the multipoint exchange of graphical information directed to these spaces including images (hard and soft copy), pointers, and filled and unfilled parametric drawing elements (points, lines, polygons and ellipses). Support for rendering out-of-band video streams within T.126 workspaces is also included. In addition, keyboard and pointing device exchanges are specified to support basic user interaction. Protocol elements for creating and referencing archived visual spaces are defined to allow pre-stored or pre-distributed graphical materials to be referenced. This protocol uses services provided by ITU-T Recommendations T.122 (MCS) and T.124 (GCC) and complies with the guidelines specified in ITU-T Recommendation T.121 (GAT). This revised version of ITU-T Recommendation T.126 introduces a number of clarifications to the previous version.