I see that you are getting. Entity Info calls it a "Guide Point".

No documented access to Guide Points ffrom Ruby.

These are all the allowed methods for entities:

["map", "any?", "add_arc", "sort", "min", "count", "fill_from_mesh", "at", "find_all", "each", "add_line", "transform_entities", "clear!", "inject", "add_cline", "add_observer", "add_3d_text", "sort_by", "max", "add_group", "select", "add_curve", "transform_by_vectors", "partition", "add_cpoint", "remove_observer", "grep", "parent", "add_image", "reject", "add_circle", "erase_entities", "member?", "add_face", "find", "model", "each_with_index", "add_text", "collect", "add_ngon", "all?", "intersect_with", "length", "entries", "add_faces_from_mesh", "detect", "zip", "[]", "add_edges", "add_instance"]

Todd