+.PP
+When \fBkeypad\fP is first enabled,
+ncurses loads the key-definitions for the current terminal description.
+If the terminal description includes extended string capabilities,
+e.g., from using the \fB\-x\fP option of @TIC@,
+then ncurses also defines keys for the capabilities whose names
+begin with "k".
+The corresponding keycodes are generated and (depending on previous
+loads of terminal descriptions) may differ from one execution of a
+program to the next.
+The generated keycodes are recognized by the \fBkeyname\fP function
+(which will then return a name beginning with "k" denoting the
+terminfo capability name rather than "K", used for curses key-names).
+On the other hand, an application can use \fBdefine_key\fP to establish
+a specific keycode for a given string.
+This makes it possible for an application to check for an extended
+capability's presence with \fItigetstr\fP,
+and reassign the keycode to match its own needs.
+.PP
+Low-level applications can use \fBtigetstr\fP to obtain the definition
+of any particular string capability.
+Higher-level applications which use the curses \fBwgetch\fP
+and similar functions to return keycodes rely upon the order in which
+the strings are loaded.
+If more than one key definition has the same string value,
+then \fBwgetch\fP can return only one keycode.
+Most curses implementations (including ncurses)
+load key definitions in the order
+defined by the array of string capability names.
+The last key to be loaded determines the keycode which will be returned.
+In ncurses, you may also have extended capabilities interpreted as
+key definitions.
+These are loaded after the predefined keys,
+and if a capability's value is the same as a previously-loaded
+key definition,
+the later definition is the one used.