Thank you for the help. I also found this .htaccess file has to be in the apllication directory, not in the root of the domain where I kept putting it. Things are working now, so I am moving on to step 2.

In step 2 of the guide, there is discussion about optimizing attachments, avatars, and such. I know in the tables that point to the attachment files the file size is recorded. If the attachments are compressed, the size will change. How does the size get corrected, or does it matter?

I'm not sure about that, I store my attachments as files. I don't think there's a tool in maintenance to update the attachment storage.

Even if it does miscount after you optimize some images, it shouldn't matter if you have infinite storage for attachments anyways.