First up, I really like minimalist software curiously capable of more than it appears. Taskpaper fits that category. Thank you!
There are situations where searches don’t work with 100% accuracy. Here’s how to replicate that.
Create some tasks and tag with with @ peskyusers. Note that I’m putting a space between @ and peskyusers to avoid creating forum tags.
Start an editor search for not @ peskyusers - all is well (probably).
Now add a blank line under one of those peskusers lines. Put a tab on it, and nothing else, or anything other than than a task. Refresh the search, and the peskyusers task will remain in a not @ peskyusers search.
This may be linked to the logic for tasks and subtasks that don’t all fit a search.
Searching for a tag shows the non-qualifying branches collapsed. Searching for not-tag will include a tagged parent if it has non-tagged subtasks.
The workaround is to keep blank lines blank.