K_K9 (reference) in projects: vim-8.2.3635

417 #define K_K9		TERMCAP2KEY('K', 'L')	// keypad 9  macro

1005     {K_K9,		(char_u *)"k9"},

1436 	case K_K9:		key = VTERM_KEY_KP_9; break;  in term_convert_key()

/vim-8.2.3635/src/
H A D	keymap.h	`417 #define K_K9 TERMCAP2KEY('K', 'L') // keypad 9 macro`
H A D	term.c	`682 {K_K9, "\316\376"}, 785 {K_K9, IF_EB("\033Oy", ESC_STR "Oy")}, // keypad 9 980 {K_K9, IF_EB("\033Oy", ESC_STR "Oy")}, // keypad 9 1314 {K_K9, "[K9]"},`
H A D	misc2.c	`1005 {K_K9, (char_u *)"k9"},`
H A D	getchar.c	`1799 case K_K9: c = '9'; break; in vgetc()`
H A D	terminal.c	`1436 case K_K9: key = VTERM_KEY_KP_9; break; in term_convert_key()`