Check out this commit for testing this fix https://github.com/ryanwyllie/moodle/commit/dcece3952d155c6926e33689551e6d9710dcbd9d Load the test form page in the browser (/test.php in your moodle instance). In "Tags" and "Tags Optional" try creating a tag with a space in it. Make sure that clicking a tag will remove it. Do the same with the keyboard and make sure that using the space bar will remove the tag. Add custom tags and also select some tags from the list. Navigate to the selected tags above the autocomplete field with the keyboard and use up and down to 'highlight' a tag. Highlighted tags selected via the keyboard will be shown as bigger than the other tags. Pressing 'space' should delete the selected tag. Repeat the navigation of the selected tags and have a tag 'highlighted'. Then go back into the search text box and enter in a tag with a space. Hitting the space when entering in the word should not delete the 'highlighted' tag. Check that keyboard navigation is possible with the different fields.