Link Formatting
Answer
Links should be recognizable as links. Generally speaking, we tend to expect links to be blue, underlined and respond to mouse over. If you are working within an established system (LibGuides, H5P, etc) and haven't changed the appearance of any links from the default, they meet WCAG guidelines.
While it is possible to meet WCAG guidelines without underlined links, it is difficult to do so and is not recommended.
Examples:
Do
Don't