Trek Fan Mapping: Letter Grades for Spectral Type Accuracy

I finally learned about data accuracy grading in SIMBAD a couple of nights ago. They have a five-level scale currently, going from A (best) to E (worst), and that letter is usually at the back end of the "Spectral type:" line item in any given star's profile data. For example, "F5V C". "F5 E" for another.

Of course, I'm making do with the data I have and the published and aired location data from the episodes and movies of the various branch series of Star Trek here...