EDIT Feb 2014 (SWS vv2.4.0 #3): these actions to select, deselect and detect (via toolbars) offscreen items have renamed in the meantime. Also, they are better documented here.
Thanks Adam (again)! It looks so simple when YOU (native english speakers) have explained it!
So, as Adam said buttons will light up to warn you about item selection. Clicking those buttons will also deselect problematic items and re-selects them on toggle (re-click).
Those actions are:
+SWS/S&M: Toolbar right item selection toggle
+SWS/S&M: Toolbar left item selection toggle
+SWS/S&M: Toolbar top item selection toggle
+SWS/S&M: Toolbar bottom item selection toggle
There are other toolbar actions that can be auto-refreshed (details and advice
HERE and
here):
+SWS/S&M: Toolbar track envelopes in touch/latch/write mode toggle
.. and Adam didn't say it but, when the new "toolbars auto refresh" option is enabled, his excellent grid actions are always consistent with REAPER's grid settings ("fixes" a little issue he explained
here):