When creating a device template it is possible to add a list of signals (description, signal type and token). When a device is created from the template, signals are also created on the model of the template.
When edits are saved, it is possible to access template signals edit pages by clicking their tags.
While adding a signal template is possible to specify whether to create a virtual signal. In the edit page it will then be possible to specify the signal formula. In the formula of a virtual signal template you can only use real signals as variables or signals of the same device template.
Signal template deletion can be done only in device template edit page, you can't delete a signal template from its edit page.