Missing restriction with foreign keys referencing partitioned tables

PG 12 added this feature, mentioned in the release notes:

        Allow <link linkend="ddl-constraints-fk">foreign keys</link>
        to reference partitioned tables (Álvaro Herrera)

When I wrote the original release notes in commit bdf595adbc, I had a
text description of "LIMITATIONS?".  Unfortunately, those limitations
were not added to the release notes, and I can't even find where the
restriction is mentioned.

How should this be improved?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +