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Yeah just my thoughts too, but playing with this, I think the header is not to right way to go because it only excists as a template file and there are no hooks for it. So if you would use this this way, you should modify every header.php in every template you have.

Not a fun job to do if you have many and I believe a plugin should work with most templates and with many or non modification to any file. So I am looking at another file at the moment to see if it would work with that file too.

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