You should add an alternative text when you are using images in Nettskjema. Alternative texts are short, descriptive texts that describes non-text content, e.g. images.
If you have invited people to respond to a form, you can set the form to send a new invitation with a given interval. This can be used in research where "diary functionality" is desirable; ex. fill out the same form every day.
You can insert a National ID Custom field if you have a reasonable need for secure identification of a person and a National ID is necessary to achieve such identification.