psql table description in psql if i do \d+, I get something like

 Schema |          Name           |   Type   | Owner  |    Size    |     Description 
--------+-------------------------+----------+--------+------------+-------------
 norsar | Routing Result          | table    | morten | 16 kB      | 
 norsar | Routing Result_id_seq   | sequence | morten | 8192 bytes | 


and so on. The last field, "Description" is always blank. Where does that field read its content? - and thereby, how can I set a description on a table? In some cases that could be quite useful - the same thing for description on columns that are shown if i do \d+ &lt;tablename&gt;.

I have tried \set ECHO_HIDDEN ON, but that didn't make it much clearer.
That shows comments that you define using the command comment on:

The following table definition:

create table foo
(
  id integer primary key, 
  name text not null
);

comment on table foo is 'This is the famous foo table';
comment on column foo.id is 'This is the primary key';
comment on column foo.name is 'This is the name of the thing';


Will then show up like this:

postgres&gt; \d+
                                List of relations
 Schema |   Name    | Type  | Owner  |    Size    |         Description
--------+-----------+-------+--------+------------+------------------------------
 public | foo       | table | thomas | 8192 bytes | This is the famous foo table
(1 row)

postgres&gt; \d+ foo
                                             Table "public.foo"
 Column |  Type   | Collation | Nullable | Default | Storage  | Stats target |          Description
--------+---------+-----------+----------+---------+----------+--------------+-------------------------------
 id     | integer |           | not null |         | plain    |              | This is the primary key
 name   | text    |           | not null |         | extended |              | This is the name of the thing
Indexes:
    "foo_pkey" PRIMARY KEY, btree (id)


postgres&gt;