Gnome GVFS added support for several attributes influencing the presentation of disks/partition to the user. GVFS uses a heuristic similar to solids to determine if a partition should be presented to the user interface, based on udev attributes amongst others. The additional attributes are used to override the heuristic by the system administrator. This is especially useful for computers with non-administrative users, as the fstab is a centralized location, i.e. family computers, schools ... The "specification" is located at https://git.gnome.org/browse/gvfs/tree/monitor/udisks2/what-is-shown.txt mappings: x-gvfs-show/hide => StorageAccess.ignored, StorageVolume.ignored x-gvfs-name => Device.description? , StorageVolume.label x-gvfs-icon => Device.icon Currently filed under fstab, but also relevant for udisks{1,2}, as the udisks backend should evaluate these attributes and be notified when the fstab changes.
This bug is reported on libsolid which is the kdelibs4 version of the solid library. It is now in maintenance mode. If you think it should still be fixed in the KDE Frameworks 5 version of solid please move it to or report a bug on frameworks-solid.
There is an open RB request for this https://git.reviewboard.kde.org/r/113587/
If you want to hide particular devices you can configure that udisks. https://wiki.archlinux.org/index.php/Udisks#Hide_selected_partitions