I would assume that Jeppesen reports the NO ALS and the XXX ALS figures. Where XXX is related to the actual length of the ALS for that particular airport.
And still, Jeppesen is a private company that relays information from the national AIP's. If a figure is not on a Jeppesen card is does not mean that it is invalid or illegal. It just means that Jeppesen didn't bother writing it down.
As an example, when flying private IR in DK, a whole different set of minimas exists for NP and circling approaches, and basically all the stuff regarding that on the Jeppesen plate is not really usable. That just mean that you have to figure the values out yourself regardless of what is written in Jeppesen
I have never seen a notam saying "halv ALS U/S" and would assume that they would just switch off all lights if that would ever happen. If only half of the ALS is put on nothing will match the ALS drawing on you chart, so I don't think thats actually legal. Maybe someone knows more here???