What is a good term to use for when I want to describe changes to the codebase that does not involve changing or adding functionality. This would include bug fixes, security patching — including library upgrades, and perhaps refactoring as well.

The term would replace the incorrect sounding “non-functional changes” in the sentence below:

“Developers should test for regressions when committing non-functional changes to the code-base”

What is the best way to phrase the above statement, ignoring for a minute the meaning of the statement itself and all the things that are wrong with it.

The term would also apply when discussing stories that do not provide direct business value and therefore are a harder “sell” during sprint planning. I.e. they can not be framed with the story template “As a user, I would like to do X.”

Therefore the term is a bucket term for work planned that is not tied directly or even indirectly to new features or enhancements. I was thinking of using something like “extra-functional” or something like that to avoid the roundabout “changes to the code base that are not directly testable apart from comprehensive regression testing.”