Originally Posted by The Golden Boy

I believe these aren't exactly correct. It's probably easier to use the numerical nomenclature.

...

Then around 1990, Deore's name was changed to Deore DX M650- parts of the MT60/62 group stayed with it- it was all the same level. Regular old Deore, Deore II and Deore DX. (MT-60, MT-62, M650)

A lower group was then added, Deore LX (M550)- it sat under Deore DX (M650), which was under Deore XT (M735).

In 1994 XTR (M900) was introduced as the line above Deore XT. DX was discontinued, and absorbed into LX.

...

DX is interesting to me- it only existed for like 3 years, it sat 2nd from the top- the first iteration kept the MT60 crank and the MT62 brakes.