A summary of what the bug is, when it might occur, etc. This might include the types of content affected. This section should provide enough information to give an idea of what is going on.
A description of applicable devices/reading systems (including OS, app version numbers, and browser if applicable) as well as whether the issue is observed in-market or sideloaded. For OS, if there is a particular "flavor", please include (ex. Samsung Android v. Pixel Android may yield very different outcomes).
Description of the expected behavior (screenshot optional)
Description of the observed behavior (screenshot optional)
A snippet of the problematic HTML/XML/CSS
Include an example EPUB file only if you have the rights to do so
Include example code if there is a workaround that you have identified
Include any example titles with their ISBNS that may be in the marketplace so that RS developers can review the issue
Include your role (content creator, publisher, RS developer, software developer, converter) and what part of the EPUB world you represent (education, trade publishing, what country or continent)