From the NannyMUD documentation

LAST CHANGE

2001-01-05

FUNCTION

NAME
        add_hook - generic info on adding hooks


LOCATION
/obj/hook.c and any object inheriting this.

SYNTAX
        varargs int add_hook(string hook_name, object obj)

DESCRIPTION
	This function registers a hook named 'hook_name' in an object. If the
	argument 'obj' is given, the hook will be registered in that object,
	else it will be registered in the object that called add_hook.


RETURN VALUES
1 on success
0 on failure


NOTE
	Objects residing in /open and /log cannot use hooks due to security
	reasons.