Extendable Limits enforce represent limited resources that expire and can later be extended or renewed.
Limits like Time and Use are used to define the periods of a trial license, activation grace period or a subscription.
Extendable limits implement the IExtendableLimit interface which defines the ExtendableValue property. The meaning of the ExtendableValue is different for each implementation. For instance the Use limit assigns the Uses property as an alias. The Time limit uses it as a number of seconds.
When an extendable limit expires then, validation will either fail or the user will be given an opportunity to extend the license. A license server can automatically extend subscriptions or use an extension code to extend the license manually.
The forms may be customized or completely replaced to fit your specific application style.
Customize the colors and icons of the forms by selecting the Theme button from the License Tab on the Ribbon.
See the How to Create a Custom Form topic for details on replacing or customizing the form.