Does your pdf sdk have features for accessible tagging, section 508 compliance?
PDFNet SDK can be used to create and process tagged, accessible, and section 508 compliant PDFs.
Since the topic of tagging and accessibility is very broad, could you please elaborate a bit on your requirements?
Are you looking to create new files, or tag existing content, extract content, … ?
To get you started, you may want to take a look at following PDFNet samples:
as well as PDFGenie tool (also available as an add-on API to PDFNet):
which lets you extract some structural info (like reading order, tables, columns, paragraphs, etc) from existing PDF documents.