CPC Subgroup H04L 63/0428 9 direct subcodes Child Classifications Navigate with arrow keys, Enter to open H04L 63/0435 H04L 63/0442 H04L 63/045 H04L 63/0457 H04L 63/0464 H04L 63/0471 H04L 63/0478 H04L 63/0485 H04L 63/0492