| Subject | English | Welsh |
| comp., MS | extra-bold | trymach (Having a font weight that corresponds to a weight class value of 800 according to the OpenType specification) |
| comp., MS | extra color | lliw ychwanegol (A color that is not part of a color scheme) |
| comp., MS | extra-light | ysgafnach (Having a font weight that corresponds to a weight class value of 200 according to the OpenType specification) |