I suggest adding a mention of `GENERATED … AS IDENTITY` as a replacement for `SERIAL` in the “Serial Types” section 8.1.4 of the “Data Types” page.
https://www.postgresql.org/docs/devel/static/datatype-numeric.html#datatype-serial
Postgres 10 sports a new `GENERATED … AS IDENTITY` for an identity column to effectively replace the `SERIAL` pseudo-type.
See “PostgreSQL 10 identity columns explained” post for a discussion of the various issues that plague `SERIAL` but not identity columns.
https://blog.2ndquadrant.com/postgresql-10-identity-columns/
Seems a shame to let the naïve reader continue using `SERIAL` without knowing about identity column feature.
—Basil Bourque