diff --git a/orm/db_utils.go b/orm/db_utils.go
index 34ddfae9..0279a14a 100644
--- a/orm/db_utils.go
+++ b/orm/db_utils.go
@@ -154,7 +154,7 @@ outFor:
 				typ := val.Type()
 				name := getFullName(typ)
 				var value interface{}
-				if mmi, ok := modelCache.getByFN(name); ok {
+				if mmi, ok := modelCache.getByFullName(name); ok {
 					if _, vu, exist := getExistPk(mmi, val); exist {
 						value = vu
 					}
diff --git a/orm/models.go b/orm/models.go
index 5cfc69b1..1d5a4dc2 100644
--- a/orm/models.go
+++ b/orm/models.go
@@ -29,39 +29,18 @@ const (
 
 var (
 	modelCache = &_modelCache{
-		cache:     make(map[string]*modelInfo),
-		cacheByFN: make(map[string]*modelInfo),
-	}
-	supportTag = map[string]int{
-		"-":            1,
-		"null":         1,
-		"index":        1,
-		"unique":       1,
-		"pk":           1,
-		"auto":         1,
-		"auto_now":     1,
-		"auto_now_add": 1,
-		"size":         2,
-		"column":       2,
-		"default":      2,
-		"rel":          2,
-		"reverse":      2,
-		"rel_table":    2,
-		"rel_through":  2,
-		"digits":       2,
-		"decimals":     2,
-		"on_delete":    2,
-		"type":         2,
+		cache:           make(map[string]*modelInfo),
+		cacheByFullName: make(map[string]*modelInfo),
 	}
 )
 
 // model info collection
 type _modelCache struct {
-	sync.RWMutex // only used outsite for bootStrap
-	orders       []string
-	cache        map[string]*modelInfo
-	cacheByFN    map[string]*modelInfo
-	done         bool
+	sync.RWMutex    // only used outsite for bootStrap
+	orders          []string
+	cache           map[string]*modelInfo
+	cacheByFullName map[string]*modelInfo
+	done            bool
 }
 
 // get all model info
@@ -88,9 +67,9 @@ func (mc *_modelCache) get(table string) (mi *modelInfo, ok bool) {
 	return
 }
 
-// get model info by field name
-func (mc *_modelCache) getByFN(name string) (mi *modelInfo, ok bool) {
-	mi, ok = mc.cacheByFN[name]
+// get model info by full name
+func (mc *_modelCache) getByFullName(name string) (mi *modelInfo, ok bool) {
+	mi, ok = mc.cacheByFullName[name]
 	return
 }
 
@@ -98,7 +77,7 @@ func (mc *_modelCache) getByFN(name string) (mi *modelInfo, ok bool) {
 func (mc *_modelCache) set(table string, mi *modelInfo) *modelInfo {
 	mii := mc.cache[table]
 	mc.cache[table] = mi
-	mc.cacheByFN[mi.fullName] = mi
+	mc.cacheByFullName[mi.fullName] = mi
 	if mii == nil {
 		mc.orders = append(mc.orders, table)
 	}
@@ -109,7 +88,7 @@ func (mc *_modelCache) set(table string, mi *modelInfo) *modelInfo {
 func (mc *_modelCache) clean() {
 	mc.orders = make([]string, 0)
 	mc.cache = make(map[string]*modelInfo)
-	mc.cacheByFN = make(map[string]*modelInfo)
+	mc.cacheByFullName = make(map[string]*modelInfo)
 	mc.done = false
 }
 
diff --git a/orm/models_boot.go b/orm/models_boot.go
index 364b68e9..7d9746d0 100644
--- a/orm/models_boot.go
+++ b/orm/models_boot.go
@@ -26,12 +26,14 @@ import (
 // prefix means table name prefix.
 func registerModel(prefix string, model interface{}) {
 	val := reflect.ValueOf(model)
-	ind := reflect.Indirect(val)
-	typ := ind.Type()
+	typ := reflect.Indirect(val).Type()
 
 	if val.Kind() != reflect.Ptr {
 		panic(fmt.Errorf("<orm.RegisterModel> cannot use non-ptr model struct `%s`", getFullName(typ)))
 	}
+	// For this case:
+	// u := &User{}
+	// registerModel(&u)
 	if typ.Kind() == reflect.Ptr {
 		panic(fmt.Errorf("<orm.RegisterModel> only allow ptr model struct, it looks you use two reference to the struct `%s`", typ))
 	}
@@ -41,9 +43,9 @@ func registerModel(prefix string, model interface{}) {
 	if prefix != "" {
 		table = prefix + table
 	}
-
+	// models's fullname is pkgpath + struct name
 	name := getFullName(typ)
-	if _, ok := modelCache.getByFN(name); ok {
+	if _, ok := modelCache.getByFullName(name); ok {
 		fmt.Printf("<orm.RegisterModel> model `%s` repeat register, must be unique\n", name)
 		os.Exit(2)
 	}
@@ -110,7 +112,7 @@ func bootStrap() {
 				}
 
 				name := getFullName(elm)
-				mii, ok := modelCache.getByFN(name)
+				mii, ok := modelCache.getByFullName(name)
 				if ok == false || mii.pkg != elm.PkgPath() {
 					err = fmt.Errorf("can not found rel in field `%s`, `%s` may be miss register", fi.fullName, elm.String())
 					goto end
@@ -123,7 +125,7 @@ func bootStrap() {
 						msg := fmt.Sprintf("field `%s` wrong rel_through value `%s`", fi.fullName, fi.relThrough)
 						if i := strings.LastIndex(fi.relThrough, "."); i != -1 && len(fi.relThrough) > (i+1) {
 							pn := fi.relThrough[:i]
-							rmi, ok := modelCache.getByFN(fi.relThrough)
+							rmi, ok := modelCache.getByFullName(fi.relThrough)
 							if ok == false || pn != rmi.pkg {
 								err = errors.New(msg + " cannot find table")
 								goto end
diff --git a/orm/models_info_f.go b/orm/models_info_f.go
index be6c9aa4..33db0d4f 100644
--- a/orm/models_info_f.go
+++ b/orm/models_info_f.go
@@ -152,6 +152,10 @@ func newFieldInfo(mi *modelInfo, field reflect.Value, sf reflect.StructField, mN
 
 	fi = new(fieldInfo)
 
+	// if field which CanAddr is the follow type
+	//  A value is addressable if it is an element of a slice,
+	//  an element of an addressable array, a field of an
+	//  addressable struct, or the result of dereferencing a pointer.
 	addrField = field
 	if field.CanAddr() && field.Kind() != reflect.Ptr {
 		addrField = field.Addr()
@@ -162,7 +166,7 @@ func newFieldInfo(mi *modelInfo, field reflect.Value, sf reflect.StructField, mN
 		}
 	}
 
-	parseStructTag(sf.Tag.Get(defaultStructTagName), &attrs, &tags)
+	attrs, tags = parseStructTag(sf.Tag.Get(defaultStructTagName))
 
 	if _, ok := attrs["-"]; ok {
 		return nil, errSkipField
@@ -188,7 +192,7 @@ checkType:
 		}
 		fieldType = f.FieldType()
 		if fieldType&IsRelField > 0 {
-			err = fmt.Errorf("unsupport rel type custom field")
+			err = fmt.Errorf("unsupport type custom field, please refer to https://github.com/astaxie/beego/blob/master/orm/models_fields.go#L24-L42")
 			goto end
 		}
 	default:
diff --git a/orm/models_info_m.go b/orm/models_info_m.go
index bbb82444..2e0905ec 100644
--- a/orm/models_info_m.go
+++ b/orm/models_info_m.go
@@ -29,31 +29,25 @@ type modelInfo struct {
 	model     interface{}
 	fields    *fields
 	manual    bool
-	addrField reflect.Value
+	addrField reflect.Value //store the original struct value
 	uniques   []string
 	isThrough bool
 }
 
 // new model info
-func newModelInfo(val reflect.Value) (info *modelInfo) {
-
-	info = &modelInfo{}
-	info.fields = newFields()
-
+func newModelInfo(val reflect.Value) (mi *modelInfo) {
+	mi = &modelInfo{}
+	mi.fields = newFields()
 	ind := reflect.Indirect(val)
-	typ := ind.Type()
-
-	info.addrField = val
-
-	info.name = typ.Name()
-	info.fullName = getFullName(typ)
-
-	addModelFields(info, ind, "", []int{})
-
+	mi.addrField = val
+	mi.name = ind.Type().Name()
+	mi.fullName = getFullName(ind.Type())
+	addModelFields(mi, ind, "", []int{})
 	return
 }
 
-func addModelFields(info *modelInfo, ind reflect.Value, mName string, index []int) {
+// index: FieldByIndex returns the nested field corresponding to index
+func addModelFields(mi *modelInfo, ind reflect.Value, mName string, index []int) {
 	var (
 		err error
 		fi  *fieldInfo
@@ -63,43 +57,39 @@ func addModelFields(info *modelInfo, ind reflect.Value, mName string, index []in
 	for i := 0; i < ind.NumField(); i++ {
 		field := ind.Field(i)
 		sf = ind.Type().Field(i)
+		// if the field is unexported skip
 		if sf.PkgPath != "" {
 			continue
 		}
 		// add anonymous struct fields
 		if sf.Anonymous {
-			addModelFields(info, field, mName+"."+sf.Name, append(index, i))
+			addModelFields(mi, field, mName+"."+sf.Name, append(index, i))
 			continue
 		}
 
-		fi, err = newFieldInfo(info, field, sf, mName)
-
-		if err != nil {
-			if err == errSkipField {
-				err = nil
-				continue
-			}
+		fi, err = newFieldInfo(mi, field, sf, mName)
+		if err == errSkipField {
+			err = nil
+			continue
+		} else if err != nil {
 			break
 		}
-
-		added := info.fields.Add(fi)
-		if added == false {
+		//record current field index
+		fi.fieldIndex = append(index, i)
+		fi.mi = mi
+		fi.inModel = true
+		if mi.fields.Add(fi) == false {
 			err = fmt.Errorf("duplicate column name: %s", fi.column)
 			break
 		}
-
 		if fi.pk {
-			if info.fields.pk != nil {
+			if mi.fields.pk != nil {
 				err = fmt.Errorf("one model must have one pk field only")
 				break
 			} else {
-				info.fields.pk = fi
+				mi.fields.pk = fi
 			}
 		}
-
-		fi.fieldIndex = append(index, i)
-		fi.mi = info
-		fi.inModel = true
 	}
 
 	if err != nil {
@@ -110,12 +100,12 @@ func addModelFields(info *modelInfo, ind reflect.Value, mName string, index []in
 
 // combine related model info to new model info.
 // prepare for relation models query.
-func newM2MModelInfo(m1, m2 *modelInfo) (info *modelInfo) {
-	info = new(modelInfo)
-	info.fields = newFields()
-	info.table = m1.table + "_" + m2.table + "s"
-	info.name = camelString(info.table)
-	info.fullName = m1.pkg + "." + info.name
+func newM2MModelInfo(m1, m2 *modelInfo) (mi *modelInfo) {
+	mi = new(modelInfo)
+	mi.fields = newFields()
+	mi.table = m1.table + "_" + m2.table + "s"
+	mi.name = camelString(mi.table)
+	mi.fullName = m1.pkg + "." + mi.name
 
 	fa := new(fieldInfo)
 	f1 := new(fieldInfo)
@@ -126,7 +116,7 @@ func newM2MModelInfo(m1, m2 *modelInfo) (info *modelInfo) {
 	fa.dbcol = true
 	fa.name = "Id"
 	fa.column = "id"
-	fa.fullName = info.fullName + "." + fa.name
+	fa.fullName = mi.fullName + "." + fa.name
 
 	f1.dbcol = true
 	f2.dbcol = true
@@ -134,8 +124,8 @@ func newM2MModelInfo(m1, m2 *modelInfo) (info *modelInfo) {
 	f2.fieldType = RelForeignKey
 	f1.name = camelString(m1.table)
 	f2.name = camelString(m2.table)
-	f1.fullName = info.fullName + "." + f1.name
-	f2.fullName = info.fullName + "." + f2.name
+	f1.fullName = mi.fullName + "." + f1.name
+	f2.fullName = mi.fullName + "." + f2.name
 	f1.column = m1.table + "_id"
 	f2.column = m2.table + "_id"
 	f1.rel = true
@@ -144,14 +134,14 @@ func newM2MModelInfo(m1, m2 *modelInfo) (info *modelInfo) {
 	f2.relTable = m2.table
 	f1.relModelInfo = m1
 	f2.relModelInfo = m2
-	f1.mi = info
-	f2.mi = info
+	f1.mi = mi
+	f2.mi = mi
 
-	info.fields.Add(fa)
-	info.fields.Add(f1)
-	info.fields.Add(f2)
-	info.fields.pk = fa
+	mi.fields.Add(fa)
+	mi.fields.Add(f1)
+	mi.fields.Add(f2)
+	mi.fields.pk = fa
 
-	info.uniques = []string{f1.column, f2.column}
+	mi.uniques = []string{f1.column, f2.column}
 	return
 }
diff --git a/orm/models_utils.go b/orm/models_utils.go
index 4c4b0f24..2a1f9d53 100644
--- a/orm/models_utils.go
+++ b/orm/models_utils.go
@@ -22,25 +22,47 @@ import (
 	"time"
 )
 
+// 1 is attr
+// 2 is tag
+var supportTag = map[string]int{
+	"-":            1,
+	"null":         1,
+	"index":        1,
+	"unique":       1,
+	"pk":           1,
+	"auto":         1,
+	"auto_now":     1,
+	"auto_now_add": 1,
+	"size":         2,
+	"column":       2,
+	"default":      2,
+	"rel":          2,
+	"reverse":      2,
+	"rel_table":    2,
+	"rel_through":  2,
+	"digits":       2,
+	"decimals":     2,
+	"on_delete":    2,
+	"type":         2,
+}
+
 // get reflect.Type name with package path.
 func getFullName(typ reflect.Type) string {
 	return typ.PkgPath() + "." + typ.Name()
 }
 
-// get table name. method, or field name. auto snaked.
+// getTableName get struct table name.
+// If the struct implement the TableName, then get the result as tablename
+// else use the struct name which will apply snakeString.
 func getTableName(val reflect.Value) string {
-	ind := reflect.Indirect(val)
-	fun := val.MethodByName("TableName")
-	if fun.IsValid() {
+	if fun := val.MethodByName("TableName"); fun.IsValid() {
 		vals := fun.Call([]reflect.Value{})
-		if len(vals) > 0 {
-			val := vals[0]
-			if val.Kind() == reflect.String {
-				return val.String()
-			}
+		// has return and the first val is string
+		if len(vals) > 0 && vals[0].Kind() == reflect.String {
+			return vals[0].String()
 		}
 	}
-	return snakeString(ind.Type().Name())
+	return snakeString(reflect.Indirect(val).Type().Name())
 }
 
 // get table engine, mysiam or innodb.
@@ -189,21 +211,25 @@ func getFieldType(val reflect.Value) (ft int, err error) {
 }
 
 // parse struct tag string
-func parseStructTag(data string, attrs *map[string]bool, tags *map[string]string) {
-	attr := make(map[string]bool)
-	tag := make(map[string]string)
+func parseStructTag(data string) (attrs map[string]bool, tags map[string]string) {
+	attrs = make(map[string]bool)
+	tags = make(map[string]string)
 	for _, v := range strings.Split(data, defaultStructTagDelim) {
+		if v == "" {
+			continue
+		}
 		v = strings.TrimSpace(v)
 		if t := strings.ToLower(v); supportTag[t] == 1 {
-			attr[t] = true
+			attrs[t] = true
 		} else if i := strings.Index(v, "("); i > 0 && strings.Index(v, ")") == len(v)-1 {
 			name := t[:i]
 			if supportTag[name] == 2 {
 				v = v[i+1 : len(v)-1]
-				tag[name] = v
+				tags[name] = v
 			}
+		} else {
+			DebugLog.Println("unsupport orm tag", v)
 		}
 	}
-	*attrs = attr
-	*tags = tag
+	return
 }
diff --git a/orm/orm.go b/orm/orm.go
index 994ed7e3..390d300f 100644
--- a/orm/orm.go
+++ b/orm/orm.go
@@ -104,7 +104,7 @@ func (o *orm) getMiInd(md interface{}, needPtr bool) (mi *modelInfo, ind reflect
 		panic(fmt.Errorf("<Ormer> cannot use non-ptr model struct `%s`", getFullName(typ)))
 	}
 	name := getFullName(typ)
-	if mi, ok := modelCache.getByFN(name); ok {
+	if mi, ok := modelCache.getByFullName(name); ok {
 		return mi, ind
 	}
 	panic(fmt.Errorf("<Ormer> table: `%s` not found, maybe not RegisterModel", name))
@@ -427,7 +427,7 @@ func (o *orm) QueryTable(ptrStructOrTableName interface{}) (qs QuerySeter) {
 		}
 	} else {
 		name = getFullName(indirectType(reflect.TypeOf(ptrStructOrTableName)))
-		if mi, ok := modelCache.getByFN(name); ok {
+		if mi, ok := modelCache.getByFullName(name); ok {
 			qs = newQuerySet(o, mi)
 		}
 	}
diff --git a/orm/orm_raw.go b/orm/orm_raw.go
index 3b945833..a968b1a1 100644
--- a/orm/orm_raw.go
+++ b/orm/orm_raw.go
@@ -286,7 +286,7 @@ func (o *rawSet) QueryRow(containers ...interface{}) error {
 
 			structMode = true
 			fn := getFullName(typ)
-			if mi, ok := modelCache.getByFN(fn); ok {
+			if mi, ok := modelCache.getByFullName(fn); ok {
 				sMi = mi
 			}
 		} else {
@@ -355,12 +355,9 @@ func (o *rawSet) QueryRow(containers ...interface{}) error {
 				for i := 0; i < ind.NumField(); i++ {
 					f := ind.Field(i)
 					fe := ind.Type().Field(i)
-
-					var attrs map[string]bool
-					var tags map[string]string
-					parseStructTag(fe.Tag.Get("orm"), &attrs, &tags)
+					_, tags := parseStructTag(fe.Tag.Get(defaultStructTagName))
 					var col string
-					if col = tags["column"]; len(col) == 0 {
+					if col = tags["column"]; col == "" {
 						col = snakeString(fe.Name)
 					}
 					if v, ok := columnsMp[col]; ok {
@@ -422,7 +419,7 @@ func (o *rawSet) QueryRows(containers ...interface{}) (int64, error) {
 
 			structMode = true
 			fn := getFullName(typ)
-			if mi, ok := modelCache.getByFN(fn); ok {
+			if mi, ok := modelCache.getByFullName(fn); ok {
 				sMi = mi
 			}
 		} else {
@@ -499,12 +496,9 @@ func (o *rawSet) QueryRows(containers ...interface{}) (int64, error) {
 				for i := 0; i < ind.NumField(); i++ {
 					f := ind.Field(i)
 					fe := ind.Type().Field(i)
-
-					var attrs map[string]bool
-					var tags map[string]string
-					parseStructTag(fe.Tag.Get("orm"), &attrs, &tags)
+					_, tags := parseStructTag(fe.Tag.Get(defaultStructTagName))
 					var col string
-					if col = tags["column"]; len(col) == 0 {
+					if col = tags["column"]; col == "" {
 						col = snakeString(fe.Name)
 					}
 					if v, ok := columnsMp[col]; ok {
diff --git a/orm/orm_test.go b/orm/orm_test.go
index bb1831f9..5e288039 100644
--- a/orm/orm_test.go
+++ b/orm/orm_test.go
@@ -227,7 +227,7 @@ func TestModelSyntax(t *testing.T) {
 	user := &User{}
 	ind := reflect.ValueOf(user).Elem()
 	fn := getFullName(ind.Type())
-	mi, ok := modelCache.getByFN(fn)
+	mi, ok := modelCache.getByFullName(fn)
 	throwFail(t, AssertIs(ok, true))
 
 	mi, ok = modelCache.get("user")