In the spirit of flexibility, Redmine lets users customize various objects inside the application. The objects can be: user, group, project, activity, version, document, spent time, issue priority, or document category. This recipe applies to any object.
Note
The custom fields feature is extremely important. It lets users customize Redmine to fit various purposes.
For example, you can change the type of tracker from Bug to Virtual server and extend this tracker with custom fields, such as RAM or Disk size, and keep track of your virtual servers. Then, you can use filtering features to find all the servers using Windows or any other custom fields that you figured out you need in your Redmine implementation.