pg_shmem_allocations & documentation

Hi,

While reading the documentation of pg_shmem_allocations, I noticed that the
off column is described as such :

"The offset at which the allocation starts. NULL for anonymous allocations
and unused memory."

Whereas, the view returns a value for unused memory:

[local]:5433 postgres(at)postgres=# SELECT * FROM pg_shmem_allocations WHERE
name IS NULL;
name | off | size | allocated_size
------+-----------+---------+----------------
¤ | 178095232 | 1923968 | 1923968
(1 row)

From what I understand, the doc is wrong.
Am I right ?

Benoit

[1] https://www.postgresql.org/docs/13/view-pg-shmem-allocations.html
[2]
https://www.postgresql.org/message-id/flat/20140504114417.GM12715%40awork2.anarazel.de
(original thread)