Specify bytes storage for enum data types

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/14/datatype-enum.html
Description:

I love Postgres !! And also its documentation !!

While reading through data types, it occurred to me that most ( if not every
) other data types has a chart on the top saying how many bytes it
occuies.
Like all numerical, date or char data types.

For enum it would be nice to have that info as well.
I am assuming it is variable ? May be 1 or 2 bytes for the definition and
the rest depending on the enum values ? 

A clarification would be nice !

Thanks
- Sumit Sengupta