Why do default VLANs appear 3 times?

[BeBoxer]

I have an SG-1100 and I've got the basics working. I want to add some more interfaces and have them be dot1q tagged going to my wireless equipment. In the Interfaces/VLAN tab of the GUI, each of the three default VLANs (WAN, LAN and OPT) show up three times. I looked that the config and they are duplicated there as well. Is this just some weird artifact? Can I safely delete the duplicates? It seems harmless but it's confusing to me because of course when I add VLANs they are only defined once.

<vlans>
		<vlan>
			<if>mvneta0</if>
			<tag>4090</tag>
			<descr><![CDATA[WAN]]></descr>
			<vlanif>mvneta0.4090</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4091</tag>
			<descr><![CDATA[LAN]]></descr>
			<vlanif>mvneta0.4091</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4092</tag>
			<descr><![CDATA[OPT]]></descr>
			<vlanif>mvneta0.4092</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4090</tag>
			<descr><![CDATA[WAN]]></descr>
			<vlanif>mvneta0.4090</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4091</tag>
			<descr><![CDATA[LAN]]></descr>
			<vlanif>mvneta0.4091</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4092</tag>
			<descr><![CDATA[OPT]]></descr>
			<vlanif>mvneta0.4092</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4090</tag>
			<descr><![CDATA[WAN]]></descr>
			<vlanif>mvneta0.4090</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4091</tag>
			<descr><![CDATA[LAN]]></descr>
			<vlanif>mvneta0.4091</vlanif>
		</vlan>
		<vlan>
			<if>mvneta0</if>
			<tag>4092</tag>
			<descr><![CDATA[OPT]]></descr>
			<vlanif>mvneta0.4092</vlanif>
		</vlan>
	</vlans>