I stumbled upon this article titled 10 Rare HTML Tags You Really Should Know. The content’s as you would expect it to be. Unfortunately the benefit of using a couple of the tags isn’t clear, but I do like the information on OPTGROUP and ACRONYM. Although do not that the indicated code for OPTGROUP is incorrect. OPTGROUP tags should actually wrap around the options that go within that group:
<select name="os"> <option>Select Your OS</option> <optgroup label="Windows"> <option value="Vista">Vista</option> <option value="XP">XP</option> </optgroup> <optgroup label="Mac"> <option value="Leopard">Leopard</option> <option value="Tiger">Tiger</option> </optgroup> </select>
I would like to think that the LABEL and FIELDSET tags are being used regularly, but perhaps they aren’t. As for WBR, I’d never heard of that one, but it’s quite interesting.