In the CREATE DOMAIN reference page of the current HEAD, it says
---
CREATE DOMAIN us_postal_code AS TEXT
CHECK(
VALUE ~ '^\\d{5}$'
OR VALUE ~ '^\\d{5}-\\d{4}$'
);
---
but I believe it should conform the standard string style now that the
default is standard_conforming_strings = on. I didn't grep if there
other pages like this.
Regards,
--
Hitoshi Harada