You need to create a static item (or book entry) for it. Then, submit the ID number of the item or entry using the same entry form as you use to log your assignments. Make sure to check off the "yes" box to indicate that you are entering it in the contest.

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Regards,
Eric Fretheim
Assistant Prep Leader, 2015 October NaNoWriMo Prep Challenge

"It is perfectly okay to write garbage-- as long as you edit brilliantly." ~C.J. Cherryh

“No, writing 50,000 words in a month is normal. You are not crazy. This is not insane.” ~Teri Brown