Sometimes I need to run Checkbox with some unusual configuration, hacked test scripts, etc. I may not upload the results to C3, but if I do, the details of what I've done will be lost and forgotten, which may cause confusion if those results are examined in the future. As an example, in working on bug #1681503, I upgraded stress-ng from version 0.07.21 to 0.07.28 on xenial and downgraded it from 0.07.28 to 0.07.21 on zesty, resulting in four submissions with results that depended on the stress-ng version installed. Even in the short term, I had to be careful to not confuse which results were which.
To help avoid confusion, it might be helpful to have a test comment field that can be entered prior to running tests and displayed as a test result on C3, ideally as the first test result shown on C3 so it's noticeable when reviewing old results. When running with an altered configuration, the tester could describe the changes made. There would, of course, still be the possibility of missing such a note, but if it were displayed prominently with the results, there'd at least be less of a chance of confusion; and if a test sequence involved several submissions, the comment field could help keep them straight even in the short term.
You mean one comment that's related to the whole testing session?
I guess it would be good to have access to it from any 'screen' that checkbox is expecting user interaction - through some key shortcut.