NN borrows a lot of symbols from traditional notation. In the Garth Brooks song NN image, a dot with a semi circle over the top appears to be a pause symbol placed over a note, you hold the note for longer than its indicated duration.), repeats, a note for an acapella section, there's a specifically noted riff in the solo, I'm not sure, but I believe the quarter note = 114 is a traditional notation symbol.

<< It was never expected to be a system that could inform someone who could not play an instrument what to play. >>

True. It was developed as a system that informed someone that could play an instrument, what to play.

Using Nashville Notation is no different in BIAB than a user importing Chords into the Chord Chart from a text file. It's just something BIAB can do that some users benefit from it in their personal workflow. NN is based on major chord chart theory.

C-D-E-F-G-A-B = 1-2-3-4-5-6-7 and the 2,3 and 6 are minors and the 7 diminished IIRC

In the other thread I used 1-4-5 because that discussion had 1-4-5 theory in other's comments. My example given there allows a novice to follow directions entering the numbers of the thread discussion without any theory or musical experience with an instrument and BIAB will provide a musical rendition of the theoretical 1-4-5 chord progression.

People that use NN and are proficient can mentally enter a chord progression into paper or the BIAB Chord Chart extremely fast. They are so use to charting a song using NN, they find it easier and PG Music accommodated those who are familiar with the system and it's included in their normal workflow.

Clearly, NN follows music theory not replaces or teach it. RayC is correct that any of the notation display types recognized by BIAB can be used to enter chords into the BIAB Chord Sheet and will display in whichever notation display option is selected as the default.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.