Coding guidelines for braces + spaces - link 404's

I have been working on a patch for Postgres. I'm curious about the suggested style for braces around if statements - some places don't include braces around an if statement body, if the if statement body is a single line.

The "Coding Conventions" don't contain any advice here (although maybe they should link to the "Developer FAQ"?) https://www.postgresql.org/docs/devel/source.html

The Postgres Wiki has a bit that says to "See also the Formatting section in the documentation," but that link 404's, so I'm not sure where it is supposed to go.

Thanks,

Kevin