Hi,

ConTeXt mkiv is the only TeX-based typesetting system that can produce
tagged PDFs and this is a really useful feature. Unfortunately, footnotes
seem to upset tagging. MWE:

\setuptagging[state=start]
\starttext
Text\footnote{Note}
\stoptext

In the resulting PDF, the structure tree seems okay to me, but the content
stream is defect:

0 g 0 G
BT
/F1 11.955168 Tf 1 0 0 1 280.5345 760.6422 Tm [<00520067>]TJ
ET
/document <</MCID 0>>BDC
BT
/F1 11.955168 Tf 1 0 0 1 70.867 702.3845 Tm [<0068>82<003200740069>]TJ
ET
EMC
BT
/F6 7.970112 Tf 1 0 0 1 94.2752 706.0772 Tm [<0052>]TJ
ET
EMC
q
1 0 0 1 70.867 131.9542 cm
[]0 d 0 J 0.3985 w 0 0 m 85.0373 0 l S
Q
/descriptiontag <</MCID 2>>BDC
0 g 0 G
EMC
BT
/F6 7.970112 Tf 1 0 0 1 61.6535 122.7515 Tm [<0052>]TJ
ET
EMC
/descriptioncontent <</MCID 4>>BDC
BT
/F5 9.96264 Tf 1 0 0 1 70.867 119.0587 Tm [<004C005100690032>]TJ
ET
EMC

Clearly, in the content (around line 10) we miss something like
/sup <</MCID 1>>BDC
I hope that this is a minor issue in the processing of footnotes. I would
very much appreciate if you could fix this bug.

Cheers,
Christoph