{%- call form.checkbox('fields__' ~ position ~ '__tdimmutable', label=_('Immutable'), id='field-f' ~ position ~ 'immutable', checked=data.get('tdimmutable', field.get('tdimmutable', '')), error=errors.tdimmutable, value='true' ) -%} {{ form.info( text=_('The value may be set once then not changed afterwards') )}} {%- endcall %}