Check out the testing commit at the end of this patch. Load the test form page in the browser (/test.php in your moodle instance). Confirm that the single select box (one at the top) doesn't have the cross in the selected item (unlike the items in the multi-select box). Select a few items from the multi-select boxes (multi, tags etc) and confirm that when the item is selected that it no longer shows up in the available options Click on some of the items you selected above and confirm that they are removed from the selected list Confirm that the items removed in the point above are now available again in the list of options for that select field (when you click the down arrow) Repeat the above steps for the multi-select boxes but this time use the keyboard navigation. The behaviour should be the same as with using the mouse. To remove selected items you need to tab focus the selection group, then use up and down to navigate the group and select the item you wish to delete. When an item is selected then hitting enter will deselect it.