The two rules for abbreviating Internet Protocol version $6($IPv$6)$ addresses are:

omit leading zeros in groups of hexadecimal digits and use dot notation.

omit leading zeros in groups of hexadecimal digits and replace only one grouping of two or more consecutive groupings of zeros in an address with a double colon.

use dot notation and break down the large integer into $4-$bit numbers.

use dot notation and replace only one grouping of two or more consecutive groupings of zeros in an address with a double colon.