Guidance
Depending on the context, it might make sense to provide a link on your form page to where users can obtain a library card if they don't already have one.
This component uses inputmode="tel" to ensure users get a numeric keyboard on mobile
devices.
Library card number
Your library card number is 14 numbers long and can be found on the back of your card.
HTML
<label for="library-card-number">Library card number</label>
<div class="gnb-form-helper-text">
Your library card number is 14 numbers long and can be found on the back of your card.
</div>
<input type="text" inputmode="tel" name="library-card-number" class="gnb-field-md" id="library-card-number" />