govuk-frontend/dist/govuk/components/hint/template-default.html

GOV.UK Frontend contains the code you need to start building a user interface for government platforms and services.

<div class="govuk-hint">
  It&#39;s on your National Insurance card, benefit letter, payslip or P60.
For example, &#39;QQ 12 34 56 C&#39;.

</div>