"look after" means use it on a very regular basis, preferably all the time.

Lack of use causes both the seals to dry out (letting all your gas escape)
and the compressor to slowly die (the lubricant for the system is carried
within the gas, so it needs constant circulation).

It doesn't need servicing until it stops blowing cold air - and even then,
it just needs a regas. Should last a few years between fillups.

every 2 years .peugeot spec

You will often hear it said that you should operate yoru a/c system
regularly so as to extend seal, and therefore, gas life.

But who wants to have a/c in the winter? Well here is something I
discovered: occasionally your windscreen fogs up inside. What is the
fastest way to de-fog?

Operate your de-mister on max heat? Wrong!

Do this, but also turn on the a/c. One of the things the a/c system
does is remove water from the air - makes even cold air an efficient
dryer, warm air even better.

So use the a/c when you need to de-fog and you will achieve the ideal
of operating yoru a/c occasionally during the winter. and you might
save your life by avoiding a collision as well!