i do this by creating my own symbols or simply adding a point to an existing symbol (you would have to save it as a new symbol most likely). Such a symbol would look something like the one here under “C”.
A pin one mark or something like that is not really helpful here becaus you could put the choke either way. But if you realy want you could put the point(s) into the silk-Layer too. That way the information is also available in the board.
If it is a symbol from the official libs always save changes to a new lib.
And remember that for kicad 4.x the symbol names need to be unique over all libraries. (So you also need to give it a new name, Or trust in your ability to always manage the library priorities correctly.)
The symbol lib table recently added to nightly will fix this in kicad 5.x
Thanks for your answers! I was thinking about wxCheckBox and wxTextCtrl to enabled begin mark and write pin number and optionaly enable/disable visibility on board. But maybe is not so important feature.