optgroup ... ⁄optgroup, optional element ⁄occurrences
The optgroup element is optional.
The optgroup element can be added multiple times per HTML5 document within the select element
Examples:
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | <!doctype html> <> <> <>...</> </> <> <> <>...</> <>...</> <>...</> </> </> </> |
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | <!doctype html> <> <> <>...</> </> <> <> <> <>...</> <>...</> <>...</> </> <> <>...</> <>...</> <>...</> </> </> </> </> |