This is the official rule book for USA Fencing. While USA Fencing uses the International Fencing Federation (FIE) rulebook as a base, not every FIE rule is or should be the same for fencing events held in the USA.
This link is to the official rulebook hosted on the USA Fencing web site.
The USA Fencing rulebook is also available for mobile devices at the following links:
Kindle version - http://assets.ngin.com/attachments/document/0085/5881/USAFencingRules9-15.mobi
Other mobile devices - http://assets.ngin.com/attachments/document/0085/5911/USAFencingRules9-15.epub