Strongly Encouraged Fixes (SEFs): issues that are violations of WCAG 2.0 and will be elevated to Required Fixes once the 508 Refresh goes into effect; they should be proactively fixed now.
ASPA-DCD classifies accessibility errors into three categories as shown below:
Required Fixes (RFs): violations that must be corrected and have direct mappings to either Section 508 or HHS accessibility guidelines.