How to write IPv6 addresses

16 groups of 4-digit hexadecial
3ffe:0507:0000:0001:0200:86ff:fe05:80fa
0000:0000:0000:0000:0000:0000:0000:0001
You can omit starting "0" in each of the groups
3ffe:507:0:1:200:86ff:fe05:80fa
0:0:0:0:0:0:0:1
In only one place, you can use "::" to denote continuous "0"
3ffe:507::1:200:86ff:fe05:80fa
::1

Usually you do not write numeric IPv6 addresses, use DNS names