Webel: Mathematica: CONVENTION: An '$E$' or '$EQ$' in a function name indicates that it is symbolic (takes Blank expression arguments), but the absence of '$E$' or '$EQ$' does not necessarily imply that it does not take Blank arguments.
Webel: Mathematica: CONVENTION: An '$E$' in a function name indicates that it is symbolic (takes Blank expression arguments). An '$E$' function can also be used with Quantity inputs and can be used to generate '$C$' compiled function variants.