The line `This syntax is not as commonly used as the one above, but we show it here...`

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/12/tutorial-join.html
Description:

Actually, it is good practice to avoid using 'cross joins' and use the
'inner join' syntax.  Most query planners might optimize both queries to run
the same plan, but the inner join reflects intent and is clearer and is
preferred in production code.