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

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

b$.$ 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.

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

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