From the "How to Use This Product" section in the PDF:
The Duelist’s Guide is made for use with the Honor + Intrigue Swashbuckling Role-Playing Game. Inside you will find a number of new resources to use with the game’s unique dueling rules, including new dueling styles, Maneuvers, and equipment. In addition, you will find new and optional rules to help you speed up combat and run it off the cuff, and also rules for lasting injuries.
Aside from material to use in combat, this guide also deals with some of the role-playing concerns involved in a character learning a dueling style, becoming a sword master in one’s own right, and taking on students of one’s own. There is even a guideline for grandmasters to create their own unique dueling styles. This addresses the issue not only mechanically, but how it is handled in-character.
Finally, there is an adventure that accompanies this guide, "Death of a Swordsman", or "The Man Who Killed Trujillo Maldonado". The story involves a sword master who is killed, and the PCs must help find out what happened. The adventure includes several sample PCs, some of whom use the new dueling styles featured in this volume. The adventure also has a guideline on how to customize the adventure for each of these PCs.