At least one user is currently suggesting to add the magento-1.9 tag to many questions, some of them even older than Magento 1.9.
Please don't blindly accept those! Adding missing version tags makes sense, but it's useless if there is no indication in the question or comments on a specific version.
Note that you don't see comments in the review queue. I always open the question in a new tab to see if the suggested edit is the result of a clarifying comment
If there is code involved, you will probably recognize magento-1 or magento2 - then feel free to add these tags. But don't assume 1.9 or 2.1 or whatever. See also: Usage of the magento-1 tag if no version is specified in question
If there is no code involved, some questions can even be answered completeley independent of the version. Not every question needs a version tag.
If the version is unclear from the question but important to answer it, add a comment to ask for the version, instead of adding a tag that might be wrong.
Thank you!
magento-1.9. All joking aside, you are 100% right. Version tags should be added only if it's really obvious from the question that the problem is for that specific version.