Well, okay, show us how to follow those instructions then.
"the :1 is short for :0001 basically" is easy enough: you get 2001::0001::0001.
Then "just put that bit at the very end" -- but which bit? If it means the ":0001", then there's two of them and they can't both go at the very end. If not, then it fails to specify which bit. Either way I don't see how these instructions are followable at all, let alone easily.
Well, okay, show us how to follow those instructions then.
"the :1 is short for :0001 basically" is easy enough: you get 2001::0001::0001.
Then "just put that bit at the very end" -- but which bit? If it means the ":0001", then there's two of them and they can't both go at the very end. If not, then it fails to specify which bit. Either way I don't see how these instructions are followable at all, let alone easily.