What is XL technology by Transparent?

What is XL technology by Transparent? Is it the network boxes?

Here is how to identify which version of Transparent you are evaluating.
Order of from good to best in their line
Plus>Super>Ultra>Reference>Reference XL (confusing) in either SS (solid state) or Tube form > Opus configured for your equipment

Transparent's first high end generation had serial numbers without the XL at the end printed on the gold plate on the networks.
Very good but the later version with the XL at the end of the serial number on the networks in my system are much better and cost $$ (IMHO in my system).

Transparent allows their cables to be upgraded to the next level (not XL but from a lower cable to a higher cable with the latest technology... Super to Ultra, Ultra to Reference, Reference to Reference XL (big price jump)).

Their Latest technology is now MM I believe.
Transparent Digital cables do not have the networks on them.
Thanks for the great info!