The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/12/ddl-constraints.html
Description:
As asked here,
https://dba.stackexchange.com/questions/270567/can-a-foreign-key-be-referring-to-the-same-table-as-the-source
the documentation specifies that a foreign key must reference another table.
But it can also be the same table.