Mesh or Single Lined
Mesh is the term for neoprene without the usual external nylon coating. It is very flexible and thus more comfortable than nylon coated neoprene and also warmer in strong winds.
Mesh should only be used in carefully chosen areas of the suit as it is more prone to damage from sharp objects.  

Super Stretch
Also known as "X" Stretch Neoprene. Developed for excellent stretch and memory. Hardwearing stretch nylon on the outside with softer super stretch nylon on the inside provides excellent comfort and fit.  

Liquid Taping
Also known as S or Super Seal. A type of rubber applied to the inside seams in liquid form to achieve a 100% watertight seal and add to the overall strength of the seam. 

Batwing zip flap
This stops any water from entering the suit through the zip and means the water has to come up and over the collar to enter the suit. So it keeps you much warmer in the winter months.