All documents must undergo accessibility compliance reviews before they are uploaded to websites. Many of the same accessibility requirements that apply to websites also apply to documents.
The newest versions of Microsoft Office have a built-in accessibility checker. Adobe Acrobat DC, the professional version of Adobe Acrobat, also comes with a built-in accessibility checker and accessibility reporting.
If you plan to export PDF files from Microsoft applications or graphic design applications like Adobe Indesign or Quark, it is strongly recommended that you also understand Adobe Acrobat DC's accessibility checker, accessibility reporting and remediation tools.
The links below cover how to address accessibility within InDesign documents, rather than having to make major changes in Adobe Acrobat DC after exporting to PDF. With InDesign, designers have the capability to add PDF tags, alt tags, and specify content order in files which stay with the document as you revise it. Used in combination with Adobe Acrobat DC for touch-up of exported PDF files, designers can achieve maximum accessibility for exported content.
It is highly recommended that you also familize yourself with PDF accessibility and complete the Adobe Acrobat DC training linked above that covers the Adobe Acrobat DC accessibility checker, accessibility reporting tools, accessibility workflow and the Lynda.com accessible PDFs training.