At least on my machine, long category titles like "Plasma Desktop Widgets" (maybe that is the only one) are cut off when details for an application are open and the list of apps is reduced to a column.
Git commit f4c58d9cff385af1b0de4645d376347b1f45c0aa by Aleix Pol. Committed on 18/11/2016 at 12:35. Pushed by apol into branch 'Plasma/5.8'. Elide category names when they're too big Long category names used to overflow, now they'll elide... M +1 -0 discover/qml/PageHeader.qml http://commits.kde.org/discover/f4c58d9cff385af1b0de4645d376347b1f45c0aa