French term (edited): chlore choc stabilise

"Shock" is used not to qualify "chlorine", but the reverse. "Shock" is shorthand for "product used for shock treatment of the pool". IOW, the French should logically be "choc chlore" or "choc chloriné" or something along those lines!

These are synonymous terms for oxidizing everything in the pool. By raising chlorine levels ten times the level of chloramines, a threshold is reached called breakpoint chlorination. When this is reached, something of a shock, or perhaps more akin to a lightning bolt, rips through the water, slashing and burning everything in its path.
When to shock? Some recommend shocking the pool when combined chlorine levels reach .3 ppm, while others suggest shocking after a party full of kids get out of the pool :-) (the theory here is that kids=urine=nitrogen+chlorine=chloramines). Others recommend it once every few weeks, whether it needs it or not. You may use your senses to determine the need for shocking. If the pool is hazy, because somebody left the filter off or forgot to add chlorine, your eyes may tell you it's time to shock. If you notice a strong chlorine smell to the water, and the eyes are burning, you may sense the need for shocking. Large doses of chlorine, in the way of shocking, are also very effective when algae has turned the water or walls a yellow or green color.
How much chlorine is required to shock? Generally, we want to raise the chlorine level up to around 10 ppm. If using cal hypo, you'll find that at least one bag per 10,000 gallons will do the trick. A little more wouldn't hurt, because if you don't reach the crucial level of breakpoint chlorination, not only is the chloramine problem not solved, but matters have been made potentially worse. Follow instructions on the package of granular CHLORINE SHOCK or non-chlorine shock, which may be potassium peroxymonosulfate.
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Cyanuric acid is a chlorine STABILIZER, providing a chemical cloak around the chlorine molecule which protects it from the sun's UV radiation, the largest killer of your chlorine. It can be a real money saver, that cyanuric, especially during the hottest times of the year.
http://poolcenter.com/chlor.htm#CL2FAQ9

When I shock my pool, should I use CHLORINE OR NON-CHLORINE SHOCK? ... I have an outdoor pool and I am told that the chlorine needs to be stabilized. Why? ...
www.focuspools.com/poolcare/Help/Swimming-Pool-FAQ.asp

OF STABILIZED CHLORINE (please specify 3" or 1" Granular or sticks. ... BAGS OF POOL SHOCK. Use as needed for quick chlorine boosts (after heavy rains, ...
www.intheswim.com/Pool-Chemicals/Pool-Chemical-Kits/ Spring-Summer-Pool-Chemical-Value-Kits-Chlorine/

How much would it have cost for them to throw in a few test strips, a rip-top packet of algaecide and a small bag of STABILIZED CHLORINE SHOCK, just to get the ...
www.amazon.com/.../detail/-/B00007E9B6?v=glance& vi=customer-reviews&show=-submittime&start-at=21

Destroys swimmer waste. • Dissolves quickly and completely. • STABILIZED CHLORINE SHOCK. • pH = 6.0. Order Info: Guardex Shock, Super Chlorinator 60 ...
www.gpspool.com/.../customerpages/catalog_updates/ 2004/Pool/2004PoolSourcerCat_44-142_Breaker-Chemicals.pdf