Why is --toc-depth limited to a value of 1-6?

[davehouser1]

I want to use --toc-depth=9 but I get the above error, why?
Looking at docx format, TOC can show up to 9 headings. Why the limit to 6?

[jgm]

Most of the formats we support don't allow more than 6. (And in general, it seems ill-advised to go beyond this level of nesting.)

That said, it probably wouldn't hurt to raise the limit to 9.