To be honest, only two sources I know of say such cord has been Legal after about 1970 for low voltage wiring: a German DIY book (not thee best thing anyway, but seems at least halfways solid) and the label on the circa 1995 rolls of cord themselves (Kopp brand). New rolls say 42V max. anyway. Still, the harmonized designation is weird.
There has been double-insulated flat cord here too, but it only looks like it can be ripped apart, actually it's solid, only with a shallow ridge. The core colors on that were yellow and white, don't even ask me where _that_ stuff came from! In some parts of our house it was plastered in to supply some ungrounded receptacles...
