Print alphanumeric characters as TAttMarker?

Is it possible to use letters or numbers as plot points in a TGraph object? Using “marker style” or another method?

I think it is not (yet) available. [url=https://root-forum.cern.ch/t/add-new-marker-style/9380/1 asked the question[/url] few years ago and Rene Brun gave a workaround at the end of the post.

It is not possible to define a text as marker. The list of available markers is listed in the TAttMarker doc.
But you can draw a piece of text at the position of graph points.
Have a look to $ROOTSYS/tutorials/graphs/graphtext.C