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- Search Engines
-- Sitemaps, Meta Data, and robots.txt
---- Meta Tags for PDF files
phranque - 11:00 pm on Dec 12, 2012 (gmt 0)Thread source:: http://www.webmasterworld.com/robots_txt/4489670.htm
after re-reading the OP i think cpollett has the answer you were looking for but you must also allow crawling by removed those pdf url patterns from robots.txt so the bot sees the X-Robots-Tag headers.
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