Extended Backus-Naur Form

Simple question really. I am after some help in understanding EBNF as a means for dissecting an email header (email header as defined in RFC 822). So if you know of any resources that can help with informing me about EBNF or with the spirit library (apart of the boost c++ library which is what I have chosen to use to implement the EBNF).

Later,
WebmasterMattD (Why are you downcast. O my soul? Why so disturbed within me? Put your hope in God, for I will yet praise him, my saviour and my God.)
http://www.webmastermattd.net
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Accountability n. Being brought before God and asked to explain your actions.
Piety n. Translating the Bible into ASCII by hand.
Evangelism n. Forcing others to counter you overtly christian sig

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