The Website functionality
1. Front end for readers
Your public facing website is also included within accessibility legislation, which usually requires WCAG AA compliance. For websites, the whole of WCAG applies, rather than the specific ebook checklist we have produced, where only the aspects that apply to static ebook files are included. Websites also have interactive content, forms, and audio visual media, all which have specific accessibility requirements. This advice also applies to books that are in HTML format.
For institutional presses, this will likely be handled by your institution, and you will have a CMS in place that ensures the accessibility (and uniform institutional look and feel) of your website. For scholar led presses, this support will not be there, however, the service who is hosting your web page will also likely use a CMS that ensure accessibility. In all scenarios, it's important to be able to check this, see Baseline Auditing
2. Back end / submission for authors
Whether the submission platform is part of the same website or is on a different system, you will also need to check this for accessibility, using the same auditing advice and the same standards (all of WCAG AA) as above.