Ctrl+4 means SIGQUIT+coredump, where is this documented, what more shortcuts are there?

Hi,

When in "cat" or "dd if=/dev/zero of=/dev/zero" or "gzip < /dev/zero >
/dev/zero", if I press ctrl+4, the program coredumps.

Doing it in ksh or sh has no effect though.

This is in OpenBSD 6.4 AMD64 from Putty on Windows.

The console interaction looks like this:

$ cat
^\Quit (core dumped)

$


Is ctrl+4 a universal SIGQUIT+coredump shortcut?

Where are the other shortcuts apart from ctrl+C, ctrl+Z, ctrl+D,
documented?

Tinker