Locking

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/16/mvcc-intro.html
Description:

There really needs to be an explicit warning that the following is invalid
in normal read committed mode:-

select foo into f from bar where id=1;
f = f + 123;
update bar set foo = f where id =1;
commit;

This is a very common and serious mistake and extremely difficult to
understand from the current documentation.