diff --git a/models/issue_label.go b/models/issue_label.go
index 3eed8ed98..befe3f192 100644
--- a/models/issue_label.go
+++ b/models/issue_label.go
@@ -62,6 +62,7 @@ type Label struct {
 	IsChecked       bool `xorm:"-"`
 }
 
+// APIFormat converts a Label to the api.Label format
 func (label *Label) APIFormat() *api.Label {
 	return &api.Label{
 		ID:    label.ID,
@@ -77,9 +78,9 @@ func (label *Label) CalOpenIssues() {
 
 // ForegroundColor calculates the text color for labels based
 // on their background color.
-func (l *Label) ForegroundColor() template.CSS {
-	if strings.HasPrefix(l.Color, "#") {
-		if color, err := strconv.ParseUint(l.Color[1:], 16, 64); err == nil {
+func (label *Label) ForegroundColor() template.CSS {
+	if strings.HasPrefix(label.Color, "#") {
+		if color, err := strconv.ParseUint(label.Color[1:], 16, 64); err == nil {
 			r := float32(0xFF & (color >> 16))
 			g := float32(0xFF & (color >> 8))
 			b := float32(0xFF & color)
diff --git a/models/issue_mail.go b/models/issue_mail.go
index 424c0ca1e..56c1e0c27 100644
--- a/models/issue_mail.go
+++ b/models/issue_mail.go
@@ -14,7 +14,7 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 )
 
-func (issue *Issue) MailSubject() string {
+func (issue *Issue) mailSubject() string {
 	return fmt.Sprintf("[%s] %s (#%d)", issue.Repo.Name, issue.Title, issue.Index)
 }
 
diff --git a/models/mail.go b/models/mail.go
index e13aedd26..f89e38e62 100644
--- a/models/mail.go
+++ b/models/mail.go
@@ -20,23 +20,24 @@ import (
 )
 
 const (
-	MailAuthActivate       base.TplName = "auth/activate"
-	MailAuthActivateEmail  base.TplName = "auth/activate_email"
-	MailAuthResetPassword  base.TplName = "auth/reset_passwd"
-	MailAuthRegisterNotify base.TplName = "auth/register_notify"
+	mailAuthActivate       base.TplName = "auth/activate"
+	mailAuthActivateEmail  base.TplName = "auth/activate_email"
+	mailAuthResetPassword  base.TplName = "auth/reset_passwd"
+	mailAuthRegisterNotify base.TplName = "auth/register_notify"
 
-	MailIssueComment base.TplName = "issue/comment"
-	MailIssueMention base.TplName = "issue/mention"
+	mailIssueComment base.TplName = "issue/comment"
+	mailIssueMention base.TplName = "issue/mention"
 
-	MailNotifyCollaborator base.TplName = "notify/collaborator"
+	mailNotifyCollaborator base.TplName = "notify/collaborator"
 )
 
-type MailRender interface {
+type mailRenderInterface interface {
 	HTMLString(string, interface{}, ...macaron.HTMLOptions) (string, error)
 }
 
-var mailRender MailRender
+var mailRender mailRenderInterface
 
+// InitMailRender initializes the macaron mail renderer
 func InitMailRender(dir, appendDir string, funcMap []template.FuncMap) {
 	opt := &macaron.RenderOptions{
 		Directory:         dir,
@@ -53,10 +54,12 @@ func InitMailRender(dir, appendDir string, funcMap []template.FuncMap) {
 	}
 }
 
+// SendTestMail sends a test mail
 func SendTestMail(email string) error {
 	return gomail.Send(&mailer.Sender{}, mailer.NewMessage([]string{email}, "Gogs Test Email!", "Gogs Test Email!").Message)
 }
 
+// SendUserMail sends a mail to the user
 func SendUserMail(c *macaron.Context, u *User, tpl base.TplName, code, subject, info string) {
 	data := map[string]interface{}{
 		"Username":          u.DisplayName(),
@@ -76,15 +79,17 @@ func SendUserMail(c *macaron.Context, u *User, tpl base.TplName, code, subject,
 	mailer.SendAsync(msg)
 }
 
+// SendActivateAccountMail sends an activation mail to the user
 func SendActivateAccountMail(c *macaron.Context, u *User) {
-	SendUserMail(c, u, MailAuthActivate, u.GenerateActivateCode(), c.Tr("mail.activate_account"), "activate account")
+	SendUserMail(c, u, mailAuthActivate, u.GenerateActivateCode(), c.Tr("mail.activate_account"), "activate account")
 }
 
+// SendResetPasswordMail sends a password reset mail to the user
 func SendResetPasswordMail(c *macaron.Context, u *User) {
-	SendUserMail(c, u, MailAuthResetPassword, u.GenerateActivateCode(), c.Tr("mail.reset_password"), "reset password")
+	SendUserMail(c, u, mailAuthResetPassword, u.GenerateActivateCode(), c.Tr("mail.reset_password"), "reset password")
 }
 
-// SendActivateAccountMail sends confirmation email.
+// SendActivateEmailMail sends confirmation email.
 func SendActivateEmailMail(c *macaron.Context, u *User, email *EmailAddress) {
 	data := map[string]interface{}{
 		"Username":        u.DisplayName(),
@@ -92,7 +97,7 @@ func SendActivateEmailMail(c *macaron.Context, u *User, email *EmailAddress) {
 		"Code":            u.GenerateEmailActivateCode(email.Email),
 		"Email":           email.Email,
 	}
-	body, err := mailRender.HTMLString(string(MailAuthActivateEmail), data)
+	body, err := mailRender.HTMLString(string(mailAuthActivateEmail), data)
 	if err != nil {
 		log.Error(3, "HTMLString: %v", err)
 		return
@@ -109,7 +114,7 @@ func SendRegisterNotifyMail(c *macaron.Context, u *User) {
 	data := map[string]interface{}{
 		"Username": u.DisplayName(),
 	}
-	body, err := mailRender.HTMLString(string(MailAuthRegisterNotify), data)
+	body, err := mailRender.HTMLString(string(mailAuthRegisterNotify), data)
 	if err != nil {
 		log.Error(3, "HTMLString: %v", err)
 		return
@@ -131,7 +136,7 @@ func SendCollaboratorMail(u, doer *User, repo *Repository) {
 		"RepoName": repoName,
 		"Link":     repo.HTMLURL(),
 	}
-	body, err := mailRender.HTMLString(string(MailNotifyCollaborator), data)
+	body, err := mailRender.HTMLString(string(mailNotifyCollaborator), data)
 	if err != nil {
 		log.Error(3, "HTMLString: %v", err)
 		return
@@ -152,7 +157,7 @@ func composeTplData(subject, body, link string) map[string]interface{} {
 }
 
 func composeIssueMessage(issue *Issue, doer *User, tplName base.TplName, tos []string, info string) *mailer.Message {
-	subject := issue.MailSubject()
+	subject := issue.mailSubject()
 	body := string(markdown.RenderSpecialLink([]byte(issue.Content), issue.Repo.HTMLURL(), issue.Repo.ComposeMetas()))
 	data := composeTplData(subject, body, issue.HTMLURL())
 	data["Doer"] = doer
@@ -171,7 +176,7 @@ func SendIssueCommentMail(issue *Issue, doer *User, tos []string) {
 		return
 	}
 
-	mailer.SendAsync(composeIssueMessage(issue, doer, MailIssueComment, tos, "issue comment"))
+	mailer.SendAsync(composeIssueMessage(issue, doer, mailIssueComment, tos, "issue comment"))
 }
 
 // SendIssueMentionMail composes and sends issue mention emails to target receivers.
@@ -179,5 +184,5 @@ func SendIssueMentionMail(issue *Issue, doer *User, tos []string) {
 	if len(tos) == 0 {
 		return
 	}
-	mailer.SendAsync(composeIssueMessage(issue, doer, MailIssueMention, tos, "issue mention"))
+	mailer.SendAsync(composeIssueMessage(issue, doer, mailIssueMention, tos, "issue mention"))
 }
diff --git a/models/release.go b/models/release.go
index a60376d97..c047b2f55 100644
--- a/models/release.go
+++ b/models/release.go
@@ -38,12 +38,14 @@ type Release struct {
 	CreatedUnix int64
 }
 
+// BeforeInsert is invoked from XORM before inserting an object of this type.
 func (r *Release) BeforeInsert() {
 	if r.CreatedUnix == 0 {
 		r.CreatedUnix = time.Now().Unix()
 	}
 }
 
+// AfterSet is invoked from XORM after setting the value of a field of this object.
 func (r *Release) AfterSet(colName string, _ xorm.Cell) {
 	switch colName {
 	case "created_unix":
@@ -151,15 +153,15 @@ func GetReleasesByRepoID(repoID int64, page, pageSize int) (rels []*Release, err
 	return rels, err
 }
 
-type ReleaseSorter struct {
+type releaseSorter struct {
 	rels []*Release
 }
 
-func (rs *ReleaseSorter) Len() int {
+func (rs *releaseSorter) Len() int {
 	return len(rs.rels)
 }
 
-func (rs *ReleaseSorter) Less(i, j int) bool {
+func (rs *releaseSorter) Less(i, j int) bool {
 	diffNum := rs.rels[i].NumCommits - rs.rels[j].NumCommits
 	if diffNum != 0 {
 		return diffNum > 0
@@ -167,13 +169,13 @@ func (rs *ReleaseSorter) Less(i, j int) bool {
 	return rs.rels[i].Created.After(rs.rels[j].Created)
 }
 
-func (rs *ReleaseSorter) Swap(i, j int) {
+func (rs *releaseSorter) Swap(i, j int) {
 	rs.rels[i], rs.rels[j] = rs.rels[j], rs.rels[i]
 }
 
 // SortReleases sorts releases by number of commits and created time.
 func SortReleases(rels []*Release) {
-	sorter := &ReleaseSorter{rels: rels}
+	sorter := &releaseSorter{rels: rels}
 	sort.Sort(sorter)
 }