chawan has a custom terminal module, so my knowledge about the standard X/Open curses is not that great.
That said, for the actual escape sequences, XTerm's ctlseqs.ms[1] is an invaluable resource. I also took many ideas from nick black's notcurses[2], and I especially recommend his notes on "sprixels".[3]
What's the best resource (paid or free) in your opinion for learning about these TTY related concepts?
I'm aware of https://www.linusakesson.net/programming/tty/index.php for example, but that doesn't go into termcap/terminfo/curses.
one of the comments mentions http://www.amazon.com/termcap-terminfo-OReilly-Nutshell-Lind... though (online https://www.scribd.com/document/831486848/Termcap-and-Termin...)