Display of foreign keys in psql

I'm having trouble coming up with a sensible translation for the last line of 
this:

peter=# \d test*    Table "public.test1"Column |  Type   | Modifiers
--------+---------+-----------a      | integer | not null
Indexes:   "test1_pkey" PRIMARY KEY, btree (a)
Referenced by: "test2_y_fkey" IN test2 FOREIGN KEY (y) REFERENCES test1(a)

Is there a magic reason why the IN is capitalized?  (Maybe "from" would be 
better anyway?)