xos/core/models/nodelabel.xproto

message NodeLabel (PlCoreBase){
     required string name = 1 [max_length = 200, content_type = "stripped", blank = False, help_text = "label name", null = False, db_index = False];
     required manytomany node->Node/NodeLabel_node:nodelabels = 2 [db_index = False, null = False, blank = True];
}