That IPv6 forwarding page is strange. IPv6 does not need forwarding.
Anyway, I am trying to find a manual for your router. A Google search shows that it is probably NL localized and probably Asian manufactured for NL ISPs. Are you able to get a manual from your ISP? Their website looks just like one of ours - no help at all. I have also tried searching on the model and not much comes back.
I’m off on holidays for a few days. I’ll be back on dinsdag/tuesday (08/08/2023).
I once named a load of servers for a helicopter company in the UK with elements. The cluster nodes were copper, silicon, etc. The cluster itself was called iron. The volumes were labelled fe_function.
It worked - it was easy to read and the bits that implied “cluster” were grouped appropriately. All the other servers had random elemental names unless they were associated in some way, in which case the group would be used. The engineers (real engineers with oil or distressingly nasty lubricants in their veins) loved it - it made sense, without being too quirky. It was very legible.
When those systems were hoicked out and replaced, the usual nonsense was applied: 2 char country code + 2 char site code etc etc ad nauseam. Followed by my absolute pet hate: 01. Oh so you might need 99 domain controllers? Yes you might, but not on one site.
Let’s face it, it is mostly AD admins who don’t get hostnames. I blame MS - their docs and blogs strive to be … authoritative or at least look so. An entire generation (possibly two) of sysadmins have been sold up the river by MS and their wankery.