+resource. If an unknown \arg{str\_id} is requested (i.e. other than wxID\_XXX
+or integer), a new record is created which associates the given string with
+a number. If \arg{value\_if\_not\_found} is \texttt{wxID\_NONE}, the number is obtained via
+\helpref{wxNewId()}{wxnewid}. Otherwise \arg{value\_if\_not\_found} is used.
+Macro {\tt XRCID(name)} is provided for convenient use in event tables.