Open Data is very tricky. We have a site for that, but their help center doesn't seem crystal clear to me:
If you have a question about …
- where to find any kind of open data
- software tools related to open data
- best practices regarding open data
- licensing and releasing open data
- open data formats and standards
- linked data, ontologies and related semantic technologies
- analysis and visualization of open data
Open Data has its own site, let them be. On the other hand, it seems that we are accepting questions about Open Knowledge (read more here), as per this meta post. It will be tricky deciding what to put, but I feel that there are similarities, and we need to be specific with what we allow. Leave that for another meta post.
The Open Standard is very similar to the Open Definition. The Open Standard was created by Open Source. Therefore, it should clearly be on-topic as it's highly related to FLOSS. That being said, I feel that questions pertaining to the Open Definition should be on topic as well.