Index: trunk/resources/data/validator/deprecated.mapcss
===================================================================
--- trunk/resources/data/validator/deprecated.mapcss	(revision 17941)
+++ trunk/resources/data/validator/deprecated.mapcss	(revision 17942)
@@ -2265,3 +2265,11 @@
 }
 
+/* #20434 */
+*[building:roof:shape] {
+  throwWarning: tr("{0} is deprecated", "{0.key}");
+  suggestAlternative: "roof:shape";
+  group: tr("deprecated tagging");
+  fixChangeKey: "building:roof:shape => roof:shape";
+}
+
 /* 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 17941)
+++ trunk/resources/data/validator/ignoretags.cfg	(revision 17942)
@@ -694,4 +694,5 @@
 K:shoulder=none
 E:service:bicycle:chaintool
+E:building:roof:shape
 ;
 ; Tags not yet decided (to remove from this section when added or moved up when deprecated)