diff --git a/src/cmd/vet/structtag.go b/src/cmd/vet/structtag.go
index 814bbda594..872fde79ce 100644
--- a/src/cmd/vet/structtag.go
+++ b/src/cmd/vet/structtag.go
@@ -54,14 +54,37 @@ func checkCanonicalFieldTag(f *File, field *ast.Field, seen *map[[2]string]token
 		if val == "" || val == "-" || val[0] == ',' {
 			continue
 		}
+		if key == "xml" && len(field.Names) > 0 && field.Names[0].Name == "XMLName" {
+			// XMLName defines the XML element name of the struct being
+			// checked. That name cannot collide with element or attribute
+			// names defined on other fields of the struct. Vet does not have a
+			// check for untagged fields of type struct defining their own name
+			// by containing a field named XMLName; see issue 18256.
+			continue
+		}
 		if i := strings.Index(val, ","); i >= 0 {
+			if key == "xml" {
+				// Use a separate namespace for XML attributes.
+				for _, opt := range strings.Split(val[i:], ",") {
+					if opt == "attr" {
+						key += " attribute" // Key is part of the error message.
+						break
+					}
+				}
+			}
 			val = val[:i]
 		}
 		if *seen == nil {
 			*seen = map[[2]string]token.Pos{}
 		}
 		if pos, ok := (*seen)[[2]string{key, val}]; ok {
-			f.Badf(field.Pos(), "struct field %s repeats %s tag %q also at %s", field.Names[0].Name, key, val, f.loc(pos))
+			var name string
+			if len(field.Names) > 0 {
+				name = field.Names[0].Name
+			} else {
+				name = field.Type.(*ast.Ident).Name
+			}
+			f.Badf(field.Pos(), "struct field %s repeats %s tag %q also at %s", name, key, val, f.loc(pos))
 		} else {
 			(*seen)[[2]string{key, val}] = field.Pos()
 		}
diff --git a/src/cmd/vet/testdata/structtag.go b/src/cmd/vet/testdata/structtag.go
index cba990fccd..363aa898bf 100644
--- a/src/cmd/vet/testdata/structtag.go
+++ b/src/cmd/vet/testdata/structtag.go
@@ -6,6 +6,8 @@
 
 package testdata
 
+import "encoding/xml"
+
 type StructTagTest struct {
 	A   int "hello"            // ERROR "not compatible with reflect.StructTag.Get: bad syntax for struct tag pair"
 	B   int "\tx:\"y\""        // ERROR "not compatible with reflect.StructTag.Get: bad syntax for struct tag key"
@@ -37,30 +39,44 @@ type JSONEmbeddedField struct {
 	unexp                     `is:"embedded,notexported" json:"unexp"` // OK for now, see issue 7363
 }
 
+type AnonymousJSON struct{}
+type AnonymousXML struct{}
+
 type DuplicateJSONFields struct {
 	JSON              int `json:"a"`
-	DuplicateJSON     int `json:"a"` // ERROR "struct field DuplicateJSON repeats json tag .a. also at testdata/structtag.go:41"
+	DuplicateJSON     int `json:"a"` // ERROR "struct field DuplicateJSON repeats json tag .a. also at testdata/structtag.go:46"
 	IgnoredJSON       int `json:"-"`
 	OtherIgnoredJSON  int `json:"-"`
 	OmitJSON          int `json:",omitempty"`
 	OtherOmitJSON     int `json:",omitempty"`
-	DuplicateOmitJSON int `json:"a,omitempty"` // ERROR "struct field DuplicateOmitJSON repeats json tag .a. also at testdata/structtag.go:41"
+	DuplicateOmitJSON int `json:"a,omitempty"` // ERROR "struct field DuplicateOmitJSON repeats json tag .a. also at testdata/structtag.go:46"
 	NonJSON           int `foo:"a"`
 	DuplicateNonJSON  int `foo:"a"`
 	Embedded          struct {
 		DuplicateJSON int `json:"a"` // OK because its not in the same struct type
 	}
+	AnonymousJSON `json:"a"` // ERROR "struct field AnonymousJSON repeats json tag .a. also at testdata/structtag.go:46"
 
 	XML              int `xml:"a"`
-	DuplicateXML     int `xml:"a"` // ERROR "struct field DuplicateXML repeats xml tag .a. also at testdata/structtag.go:54"
+	DuplicateXML     int `xml:"a"` // ERROR "struct field DuplicateXML repeats xml tag .a. also at testdata/structtag.go:60"
 	IgnoredXML       int `xml:"-"`
 	OtherIgnoredXML  int `xml:"-"`
 	OmitXML          int `xml:",omitempty"`
 	OtherOmitXML     int `xml:",omitempty"`
-	DuplicateOmitXML int `xml:"a,omitempty"` // ERROR "struct field DuplicateOmitXML repeats xml tag .a. also at testdata/structtag.go:54"
+	DuplicateOmitXML int `xml:"a,omitempty"` // ERROR "struct field DuplicateOmitXML repeats xml tag .a. also at testdata/structtag.go:60"
 	NonXML           int `foo:"a"`
 	DuplicateNonXML  int `foo:"a"`
 	Embedded         struct {
 		DuplicateXML int `xml:"a"` // OK because its not in the same struct type
 	}
+	AnonymousXML `xml:"a"` // ERROR "struct field AnonymousXML repeats xml tag .a. also at testdata/structtag.go:60"
+	Attribute    struct {
+		XMLName     xml.Name `xml:"b"`
+		NoDup       int      `xml:"b"`                // OK because XMLName above affects enclosing struct.
+		Attr        int      `xml:"b,attr"`           // OK because <b b="0"><b>0</b></b> is valid.
+		DupAttr     int      `xml:"b,attr"`           // ERROR "struct field DupAttr repeats xml attribute tag .b. also at testdata/structtag.go:76"
+		DupOmitAttr int      `xml:"b,omitempty,attr"` // ERROR "struct field DupOmitAttr repeats xml attribute tag .b. also at testdata/structtag.go:76"
+
+		AnonymousXML `xml:"b,attr"` // ERROR "struct field AnonymousXML repeats xml attribute tag .b. also at testdata/structtag.go:76"
+	}
 }