I think you have a good start.

A(blue part marker) and B(green part marker) are called "substyles" and yes, A is typically the verse and B the chorus, because the B substyle is generally 'busier' or more intense.

While the change to a different substyle results in a drum fill, that can now be turned off if you have a recent version of BIAB. Also, the intensity of fills depends greatly on the style selected.

In jazz, a form of Intro, AABA, Tag might be done as B,A,A,B,A,B

There is a possibility of using a style with more than two substyles, called a Multistyle. BIAB introduced some of these quite a few years ago, but if I recall correctly, they were MIDI-oriented. It was possible to click through more than A and B; you could get C, D and more and they used different colors.

I believe if you wish to build and save your own style, it should be possible to combine RealTracks in a way to construct a user style that would allow you to do this. Often just changing the drums used makes a major difference in the feel of a song.

You can read more about this by going to Help, Help Index, Substyles. They discuss pre-verse, interlude, drum fills and more.

Also note, you do not have to change the feel of the song by using substyles. You can press F5 (Bar Settings menu) and change the style at any measure. I suspect this technique is used more often than multistyles.

Let me know if this helped you, and ask your questions.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.