[NTG-context] Accessibility and Tagged PDF/A, Footnotes showing

Hello Hans and Dr. Dominik Klein! Today I found a Thread about Accessibility from last Juli! I work at the University in Vienna, and I work with students, who are blind or have a see handicap. So I read this Thread today. Last year in Summer I began to read the manual of Context. I have a question to this discussion, it is nessesary to know: How can footnotes be shown in the PDF/A tagged PDF, in a text? What I mean something, that shows in the Text the text from the footnote, when I click on the number from the footnote. Maybe with a tooltip? Or what is the right way? Which command? Ursula Hermann