I suggest reading that now if you haven't done so.
Intrigued? Read more about ZL Specials here:
* The 'BRD Zapper - A quick and easy ZL Special
* The '8JK revisited and the 'BRD zapper
* Jonathan Hare's ZL special for the 2m band
* VK2ZIW ZL Special for 6m
* W4RNL on the ZL Special & more here
* JA6HIC's ZL Specials
* W7EL's FD Special
PS: Do you sometimes come across terms that you're unfamiliar with? The Illustrated International Ham Radio Dictionary can help. Available in both ebook and paperback it's great value. Find out more here.