The following letter combinations are currently or have recently been used on various Mercedes-Benz models: A, B, C, CL, CLA, CLK, CLS, E, G, GL, GLA, GLK, M or ML, R, S, SL, SLS, SLK and V. It's probably a fair assumption that to anyone who doesn't regularly frequent CarAdvice or other automotive sites that those letters give little clue as to what type and size of vehicle you're referring to.
Sources who have spoken to both Car and Driver and the official Mercedes-Benz museum's PassionBlog have confirmed that the M-Class name, as well as the ML badge, will be given the old heave-ho when the SUV is given a facelift in 2015.
The almost two decade old name will be replaced by the GLE-Class designation, with GL being the prefix for all future Mercedes-Benz SUVs and E indicating that the vehicle is around the same size as the E-Class sedan and wagon. As a result, the upcoming M-Class "coupe" is likely to dubbed the GLE-Class Coupe instead of MLC, and the next generation GLK will be christened the GLC.
If these reports prove to be true, it will continue a process that started when Mercedes-Benz replaced the CLK with the E-Class coupe and convertible. More recently, for its range-topping coupe, the company has junked the CL moniker in favour of the more easily understood S-Class Coupe title.