When you update a feature's status (to Awaiting feedback, Planned, Released, etc), by default you have several pre-populated options to explain the transition.
You can (and should!) also create your own custom saved responses. There are two ways to do this:
1. Edit custom saved responses all at once
Select "Settings" from the left-hand navigation.
Select "Custom responses" from the list on the right-hand side. Then click "Create custom response".
You can now select the relevant status and enter the response.
Click "Create" to save it.
To edit any saved response, just click "Edit" next to the saved response:
And update your response:
2. Create a new custom saved response on the fly
When changing the status of a feature, you can customize the response. To save it, simply check the box labelled "Save response for future use".