[TASK] Default Marker type and usage

Resources/Private/Templates/Mail/Index.html

@@ -30,7 +30,12 @@
 							<td>{marker.marker}</td>
 							<td>
 								<f:if condition="{marker.type}">
-									<f:translate key="{marker.type}">{marker.type}</f:translate>
+									<f:then>
+										<f:translate key="{marker.type}">{marker.type}</f:translate>
+									</f:then>
+									<f:else>
+										<f:translate key="backend.marker.type.string" />
+									</f:else>
 								</f:if>
 							</td>
 							<td>
@@ -47,7 +52,14 @@
 								</f:if>
 							</td>
 							<td>
-								{marker.usage}
+								<f:if condition="{marker.usage}">
+									<f:then>
+										{marker.usage}
+									</f:then>
+									<f:else>
+										<![CDATA[{]]>{marker.marker}<![CDATA[}]]>
+									</f:else>
+								</f:if>
 							</td>
 							<td>
 								<f:translate key="{marker.description}">{marker.description}</f:translate>