NPt destination prefix UI confusing

[mcfly9]

Hi,

When setting up an NPt entry, the destination IPv6 prefix section allows you to select a known (delegated) subnet as the destination of the mapping:

My ISP delegates a /56 prefix from which I delegate /64 subnets. Today I realized what the naming in the dropdown actually means the "IPv6 Prefix ID":

• WAN/65 -> 41 network id (hex 41 = dec 65)
• WAN/10 -> 10 network id (hex 10 = dec 16)

I found it non-trivial at first to understand what the "WAN/<networkidindec>" text means, as I started diagnosing where did I fat-finger a /64 into a /65...

Maybe worth clarifying this UI by modifying the hint to something like "WAN / prefix ID: 41"...?