Apache .conf files only really support single-line comments, starting with the pound sign (#). I came up with a silly hack for multi-line comments that seems to work, so I'm putting it out there either to help other people, or be brutally taken down by people who are more savvy than I am.
Basically, make up a non-existent runtime variable and use it in an
<IfDefine> block. Because the variable doesn't exist, nothing between the tags should be executed. So for example: