diff --git a/src/dav/calencoder.rs b/src/dav/calencoder.rs
index 5cd40ef..1016a20 100644
--- a/src/dav/calencoder.rs
+++ b/src/dav/calencoder.rs
@@ -262,14 +262,56 @@ impl<C: CalContext> QuickWritable<C> for ResourceType {
 // --------------------------- DAV::error ------------------------------------
 impl<C: CalContext> QuickWritable<C> for Violation {
     async fn write(&self, xml: &mut Writer<impl AsyncWrite+Unpin>, ctx: C) -> Result<(), QError> {
+        let mut atom = async |c| xml.write_event_async(Event::Empty(ctx.create_cal_element(c))).await;
+
         match self {
-            Self::ResourceMustBeNull => {
-                let start = ctx.create_cal_element("resource-must-be-null");
-                xml.write_event_async(Event::Empty(start)).await?;
-           },
-            _ => unimplemented!(),
-        };
-        Ok(())
+            //@FIXME
+            // DAV elements, should not be here but in RFC3744 on ACLs
+            // (we do not use atom as this error is in the DAV namespace, not the caldav one)
+            Self::NeedPrivileges => xml.write_event_async(Event::Empty(ctx.create_dav_element("need-privileges"))).await,
+
+            // Regular CalDAV errors
+            Self::ResourceMustBeNull => atom("resource-must-be-null").await,
+            Self::CalendarCollectionLocationOk => atom("calendar-collection-location-ok").await,
+            Self::ValidCalendarData => atom("valid-calendar-data").await,
+            Self::InitializeCalendarCollection => atom("initialize-calendar-collection").await,
+            Self::SupportedCalendarData => atom("supported-calendar-data").await,
+            Self::ValidCalendarObjectResource => atom("valid-calendar-object-resource").await,
+            Self::SupportedCalendarComponent => atom("supported-calendar-component").await,
+            Self::ValidCalendarObjectResource => atom("valid-calendar-object-resource").await,
+            Self::SupportedCalendarComponent => atom("SupportedCalendarComponent").await,
+            Self::NoUidConflict(href) => {
+                let start = ctx.create_cal_element("no-uid-conflict");
+                let end = start.to_end();
+
+                xml.write_event_async(Event::Start(start.clone())).await?;
+                href.write(xml, ctx.child()).await?;
+                xml.write_event_async(Event::End(end)).await
+            },
+            Self::MaxResourceSize => atom("max-resource-size").await,
+            Self::MinDateTime => atom("min-date-time").await,
+            Self::MaxDateTime => atom("max-date-time").await,
+            Self::MaxInstances => atom("max-instances").await,
+            Self::MaxAttendeesPerInstance => atom("max-attendees-per-instance").await,
+            Self::ValidFilter => atom("valid-filter").await,
+            Self::SupportedFilter { comp, prop, param } => {
+                let start = ctx.create_cal_element("supported-filter");
+                let end = start.to_end();
+
+                xml.write_event_async(Event::Start(start.clone())).await?;
+                for comp_item in comp.iter() {
+                    comp_item.write(xml, ctx.child()).await?;
+                }
+                for prop_item in prop.iter() {
+                    prop_item.write(xml, ctx.child()).await?;
+                }
+                for param_item in param.iter() {
+                    param_item.write(xml, ctx.child()).await?;
+                }
+                xml.write_event_async(Event::End(end)).await
+            },
+            Self::NumberOfMatchesWithinLimits => atom("number-of-matches-within-limits").await,
+        }
     }
 }
 
diff --git a/src/dav/caltypes.rs b/src/dav/caltypes.rs
index c803c0c..29dc02f 100644
--- a/src/dav/caltypes.rs
+++ b/src/dav/caltypes.rs
@@ -614,9 +614,11 @@ pub enum Violation {
     /// containing a single valid VTIMEZONE component.
     ValidCalendarData,
 
-    /// (DAV:needs-privilege): The DAV:bind privilege MUST be granted to
+    ///@FIXME should not be here but in RFC3744
+    /// !!! ERRATA 1002 !!!
+    /// (DAV:need-privileges): The DAV:bind privilege MUST be granted to
     /// the current user on the parent collection of the Request-URI.
-    NeedsPrivilege,
+    NeedPrivileges,
 
     ///  (CALDAV:initialize-calendar-collection): A new calendar collection
     /// exists at the Request-URI.  The DAV:resourcetype of the calendar
@@ -693,7 +695,7 @@ pub enum Violation {
     /// the resource will be stored;
     MaxAttendeesPerInstance,
 
-    /// The CALDAV:filter XML element (see
+    /// (CALDAV:valid-filter): The CALDAV:filter XML element (see
     /// Section 9.7) specified in the REPORT request MUST be valid.  For
     /// instance, a CALDAV:filter cannot nest a <C:comp name="VEVENT">
     /// element in a <C:comp name="VTODO"> element, and a CALDAV:filter