How to list and delete terminfo?

I have installed some custom terminfo with tic command. How do I list all terminfo in the database (e.g. with infocmp) and how to delete specific terminfo? Here's my idea as of right now: On Linux, system-wide terminfo database is located in /lib/terminfo (Debian), /usr/share/terminfo (Arch), and /usr/share/lib/terminfo (Solaris); On macOS, system-wide terminfo database is located in /usr/share/terminfo; User-defined terminfo database is in ~/.terminfo. For now I believe the terminfo database items could be altered by deleting the compiled items in those directories. So further questions are: Why are items terminfo organized in two hex digit directories (e.g. 31, 7a)? How are they organized? And if I write a new terminfo with tic into the database, but with an existent name, is the previous terminfo overwritten?