Generally, most regions have a semi-standard or standard set of symbols that is used to denote electrical wiring devices, such as switches and receptacles, on building electrical plans/blueprints. A representative subset of symbols used in North America is shown below, for those who are not familiar with the symbology used here.
However, none of the sources I have been able to find in my (admittedly limited) research have depicted a symbol for an electrical inlet, such as the ones used when houses are fitted so that a portable generator can provide standby power through some sort of transfer means.
Is there such a symbol, either in a standard somewhere or as a de facto convention? Or, am I left with simply using a symbol for a specialized receptacle (not shown above, but there are de facto quasi-standard symbols for such out there) and then using a note to denote that it is an inlet of a certain type?