When on, the |tagstack| is used normally. When off, a ":tag" or ":tselect" command with an argument will not push the tag onto the tagstack. A following ":tag" without an argument, a ":pop" command or any other command that uses the tagstack will use the unmodified tagstack, but does change the pointer to the active entry. Resetting this option is useful when using a ":tag" command in a mapping which should not change the tagstack.