Index: trunk/resources/data/validator/deprecated.mapcss
===================================================================
--- trunk/resources/data/validator/deprecated.mapcss	(revision 16993)
+++ trunk/resources/data/validator/deprecated.mapcss	(revision 17017)
@@ -2047,3 +2047,11 @@
 }
 
+/* #19739 */
+*[natural=sink_hole] {
+  throwWarning: tr("{0} is deprecated", "{0.tag}");
+  suggestAlternative: "natural=sinkhole";
+  group: tr("deprecated tagging");
+  fixAdd: "natural=sinkhole";
+}
+
 /* When tags are deprecated they should be added to ignoretags.cfg too. */
Index: trunk/resources/data/validator/ignoretags.cfg
===================================================================
--- trunk/resources/data/validator/ignoretags.cfg	(revision 16993)
+++ trunk/resources/data/validator/ignoretags.cfg	(revision 17017)
@@ -695,4 +695,5 @@
 K:generator:type=solar_photovoltaic_panels
 K:building=part
+K:natural=sink_hole
 ;
 ; Tags not yet decided (to remove from this section when added or moved up when deprecated)