Yes.
There is no standard location in which a filter will look for labels; you have to tell the filter (or other client) where the labels are. If the user lands on a page that does not link to your labels, the filter won’t “auto-magically” find the labels.rdf file.
However, the tag:
- is short
- is the same on every page
So it’s relatively easy to ensure that each page includes the same tag. If you use an external stylesheet, you’ll already be familiar with including a Link tag on each page.
If you use a template for your pages, make sure you include the Link tag in it!
The PICS tag is a PICS version of your RDF label. It does not link to anything and so must be present on your pages to enable PICS filters to read your content label.