As discussed on the mailing list  there seems to be consensus that case insensitive search in Jenkins is much more intuitive. This unfortunately is an opposite to the situation available in Jenkins as of this issue creation . In a context of changes in
JENKINS-40718 (and the same approach in other places) it would be no longer possible to find FAILED jobs just by typing "fail" ("FAIL" would be required). This is counterproductive and misleading.
This issue assumes change the default behavior for newly crated users and for an anonymous user.
In addition it would be good to consider (probably as a separate issue to do not postpone the main action) a possibility to change that behavior for users that haven't intentionally opt-in to have case sensitive search. Unfortunately it can be impossible to determine that situation. Therefore maybe it would be beneficial (to prevent a "regression" related to
JENKINS-40718 and similar changes) to reset that behavior and require from an user to opt-in to it once more - however, it could be somehow clumsy in the implementation (e.g. two values in XML for the same feature). Suggestions for that are welcome.