StoreFront 2.6 mandatory store explained
In some organizations there is a requirement to prevent users from removing auto-provisioned applications or even to hide the plus sign that opens up the application catalogue for users [...]
StoreFront 2.6 installation and upgrade
If you want to fully utilize new features provided by XenApp and XenDesktop 7.6 you have to upgrade an existing StoreFront installation to version 2.6 which comes with core [...]