silverstripe-framework/templates/SilverStripe/Forms/CreditCardField.ss

<span id="{$Name}_Holder" class="creditCardField">
	<input $getAttributesHTML('id', 'name', 'value', 'tabindex') name="{$Name}[0]" value="{$ValueOne}" $TabIndexHTML(0)/>
	-
	<input $getAttributesHTML('id', 'name', 'value', 'tabindex') name="{$Name}[1]" value="{$ValueTwo}" $TabIndexHTML(1)/>
	-
	<input $getAttributesHTML('id', 'name', 'value', 'tabindex') name="{$Name}[2]" value="{$ValueThree}" $TabIndexHTML(2)/>
	-
	<input $getAttributesHTML('id', 'name', 'value', 'tabindex') name="{$Name}[3]" value="{$ValueFour}" $TabIndexHTML(3)/>
</span>