Some speaker manufacturers use "planar" type ribbon speakers. They can be loosely classified as ribbon since they still utilize a radiating ribbon to create sound however they do not come close to the benefits of the true ribbon in terms of highs (true ribbons should produce 40kHz and up), transients and clarity. Planar ribbons are much cheaper and easier to produce since they can be mass produced while true ribbons are 100% hand-made because of the delicateness of the material used.
Rule of thumb... planar ribbons usually - waland ridges yung ribbons.