I'm with my BSAC colleagues on this...there is a gradual progression of difficulties and skills involved in diving not only depending on depth but also on water temperature, visibility, current yes or no, shore or boat dives, etc
Belgian CMAS (NELOS) certification includes decompression techniques and dives from level 2 (CMAS 2* Diver = between PADI AOW and rescuediver). This includes calculating deco profiles using tables and computer, calculating bottom time, rules of thirds, calculating air usage, etc. This also obviously includes calculation of PP02 and PPN2 and it's effects (paul bert).
Depth limits are:
CMAS 1 * Diver (PADI OW/AOW) = 66 feet
CMAS 2 * Diver (PADI AOW/rescuediver) = 100 feet
CMAS 3 * Diver new style (PADI DM) = 130 feet
CMAS 3 * Diver old style (PADI DM) = 190 feet
Above CMAS 3 * = depth limit of US NAVY 93 tables (= 300 feet)
From 2 * onwards you may make deco dives as long as you keep to your depth limit. Obviously this does not happen often if you have a depthlimit of 100 feet. But the standard tank used in Belgium is 119HP tank so it still is feasible to get slight deco time.
The extreme depths that anything above CMAS/NELOS 3 * dives may dive to (and be insured) is obviously an anachronism in current knowledge of bubble theory, CNS, etc (the old NAVY tables allowed diving to PP02 2.0). But CMAS/NELOS has the attitude that if you are above a certain certification you should know what you can and cannot do.
In below link you'll find our currently still in use tables.
http://wiki.nelos.be/images/4/43/BND_Tabellen_1.0.0.pdf
I understand that there are agencies that will divide between recreational and technical diving. If you use the definition that any dive with a ceiling (be it artificial or real) is a technical dive then some dives we do may be called technical. Our certification agency however clearely thinks otherwise as do other european agencies since deco diving is part of their curiculum.