Use case or problem
When you are migrating a lot of existing documents to Obsidian, there could be an unknown number of files without any tags. It would be helpful to return the list of files that don’t have any tags at all so appropriate tags can be added.
Proposed solution
Search currently supports tag:#tag-name. Adding tag:unknown or tag:none could return the list of matches without a tag.
Current workaround (optional)
Compare the list of all *.md files against the list of all *.md that have a tag and output the file names that are missing tag values.
find . -iname "*md" | sort > ~/Desktop/f1.txt
find . -iname "*md" -exec grep -l '^\#[a-zA-Z]' {} \; | sort > ~/Desktop/f2.txt
comm -23 ~/Desktop/f1.txt ~/Desktop/f2.txt