What CUPS LP/LPR consult for Configuration File(s)

Executing:

strace -f lp /etc/hosts

gives us this gem on what the CUPS printer tool is looking for in user-defined and system-defined configuration settings:

access("printers.conf", R_OK)           = 0
openat(AT_FDCWD, "/root/.cups/lpoptions", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/cups/lpoptions", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/cups/client.conf", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/root/.cups/client.conf", O_RDONLY) = -1 ENOENT (No such file or directory)
access("/run/cups/cups.sock", R_OK)     = 0