The OpenType standard, when talking about the name table at the following address:
Mentions the following:
"Font Subfamily name. The Font Subfamily name distiguishes the font in a group
with the same Font Family name (name ID 1). This is assumed to address style
(italic, oblique) and weight (light, bold, black, etc.). A font with no
particular differences in weight or style (e.g. medium weight, not italic and
fsSelection bit 6 set) should have the string "Regular" stored in this position."
But the regular DejaVu fonts have "Book" here, contrary to the standard
recommendation that they should use "Regular".
Do you still experience this issue with newer soft?
Please check the status of your issue.