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I am looking for the file extension site carrying searcheable database of files :by extension, by ID in ASCI and Hex, by keyword. Of course by extension I see many, how about file ID? Will I be lucky to find one?

Well, while you may have seen many for extension, I'll post this one here anyways, since it's pretty much the holy grail of extension databases: http://filext.com.

I'm not sure about tags, but you could try this tool and see if it turns up a match (look for TrID): http://mark0.net.

Good luck!