Web Content Accessibility Guideline (WCAG) 2.4.8 Location, requires that information about the user's location within a set of web pages is available. This is a Level AAA requirement but it's pretty easy to reach this level on most pages. How? By using breadcrumbs.
Breadcrumbs are the links at the top of a site that show you the path to the current page. This is the path to the 100 Days:
Accessibility Home / Digital Accessibility / 100 Days of A11y
Relates to: 2.4.8 Location (Level AAA)