DEF Program Documents
API Diesel Exhaust Fluid Certification Program Overview
This document provides an overview of the program and explanation of the requirements to become an API-licensed diesel exhaust fluid marketer and use the API DEF Certification Marks.
Step-by-Step Guide for DEF Applicants and Licensees
This document provides an array of step-by-step instructions and screenshots to assist the user with the online application system and license maintenance.
Branding Guide
This eleven-page guideline is intended to help licensees display and use the API Quality Marks properly. A downloadable Branding Guide is available in PDF format.
