I know we’re talking about electrical code and all so it’s expected to be a bit pedantic but you’re really stretching to find fault in FoundWaldo’s statement. His use of ‘receptacle’ is clearly intended to refer to a NEMA-5 outlet. You could have just as easily cited any light fixture with a E-26 socket as an example of a NEMA outlet that can be used on a dimmer.
The answer is it is against code to have a dimmer installed powering standard outlets, as the OP in this thread has done. Either the dimmer needs to be removed or the device needs to be changed to something compatible.
The dimming socket you’ve mentioned shows the lengths one must go through in order to have a dimming outlet and minimize any accidental confusion.