(copied from http://www.physics.leidenuniv.nl/organisation-ref/support-departments/ict-group/ict-group-guidelines-hidden)

These guidelines are intended to optimize the working of the LION computer environment, and minimize the risk of network break down. If in the course of your duties it becomes necessary to deviate from these rules, please contact system management.

1. System management supports the following operating systems: Windows 10,11, RedHat Linux.
2. Operating systems will be installed by system management only. This also goes for software emulating the functionality of operating systems. The operating system for standard office PC's is Windows 10. The build-in administrator account is administered by system management.
3. Users of Windows 10 have to log on to the PHYSICS domain. User accounts on Windows 10 workstations are not allowed.
4. It is not allowed to connect any equipment with an ethernet interface to the network, due to possible conflicts with other equipment. Portable computers can be connected after permission and configuration by system management. The network parameters of computers and other equipment may only be changed by system management. The moving of network computers/equipment to another network wall plate, or its permanent removal, has to be reported to system management.
5. Changes to the hardware configuration are done by system management.
6. It is not allowed to change the language settings of the operating system.
7. It is not allowed to install software that isn't associated with the task or function of the user; such software is a frequent source of problems.
8. Passwords should be kept privately; exchange of passwords may comprimize the security of the system.
9. All users get a home directory on the LION servers, of which a backup is made every day. The available space for data on the personal P: drive is 6 Gb. The available space for mail on the PHYSICS mailserver is 6 Gb.
10. Hacking, sniffing, and scanning are not allowed.
11. Violations of these rules will result in the decoupling of the offending equipment from the network, and/or the blocking of the account of the user.
12. The ending of contract or study is reported to system management. Student accounts will be deleted after two months, accounts of staff after three months, and accounts of guests when their arranged period of stay expires.