diff --git a/nstruct/tags.go b/nstruct/tags.go
index acf57e0..8d218aa 100644
--- a/nstruct/tags.go
+++ b/nstruct/tags.go
@@ -170,6 +170,8 @@ func (p *TagParser) Info(field, tag string) (nmap.SMap, error) {
 //
 //	Int64String int64 `json:",string"`
 //
+//  Field int `json:",string,formatter=2006-01-02"`
+//
 // Returns:
 //
 //	{
@@ -181,7 +183,8 @@ func (p *TagParser) Info(field, tag string) (nmap.SMap, error) {
 func ParseTagValueDefault(field, tagVal string) (mp nmap.SMap, err error) {
 	ss := nstr.SplitTrimmed(tagVal, ",")
 	ln := len(ss)
-	if ln == 0 || tagVal == "," {
+
+	if tagVal == "," {
 		return nmap.SMap{"name": field}, nil
 	}
 
@@ -195,10 +198,22 @@ func ParseTagValueDefault(field, tagVal string) (mp nmap.SMap, err error) {
 	}
 
 	// ln > 1
-	mp["name"] = ss[0]
+	// valid field name
+	if ss[0] != "-" {
+		mp["name"] = ss[0]
+	}
 	// other settings: omitempty, string
-	for _, key := range ss[1:] {
-		mp[key] = "true"
+	for _, tt := range ss[1:] {
+		if tt == "" {
+			continue
+		}
+		// kv
+		if !strings.ContainsRune(tt, '=') {
+			mp[tt] = "true"
+			continue
+		}
+		key, val := nstr.TrimCut(tt, "=")
+		mp[key] = val
 	}
 	return
 }
diff --git a/nstruct/tags_test.go b/nstruct/tags_test.go
new file mode 100644
index 0000000..6bd29b3
--- /dev/null
+++ b/nstruct/tags_test.go
@@ -0,0 +1,10 @@
+package nstruct
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestParseTagValueDefault(t *testing.T) {
+	fmt.Println(ParseTagValueDefault("haha", "-,"))
+}