Thanks v much, MitkOK, but where and how does that go in the page, please? I've looked at it on the php site, but don't follow how it is supposed to go.
I mean, say the page is 'content/display.php', do you have to state chmod is for that particular page, or is the meaning just assumed for whatever page it is used on, please?
The tutorial I am trying to follow through says to make the page read-only. I had assumed it was so that it couldn't be hacked - that any changes made couldn't be saved.
I can't really think of any other reason for doing it.
"Read only" is a file access issue, not a PHP issue. If your web server is set up correctly, only authorized users should be able to change your page anyway, so read-only will only keep you from doing so.
Most service providers have a way to set permissions on files. A common issue with Perl scripts, for example, is improper permissions, so service providers have to let you change them. (PHP usually doesn't have this problem.)