What is R/C/L on a LED dimmer?

Dimmers are also sometimes categorized by their compatibility with load(s) types

There are three popular types of traditional lighting loads dimmers are designed to compatible with :

Using this classification, we have:
-R dimmer which can be compatible with R type load
-RC dimmer which can be compatible with R type and C type load
-RL dimmer which can be compatible with R type and L type load
-RLC dimmer which can be compatible with all three types load