old_contents: from wtforms import Form, SubmitField, BooleanField, TextField, SelectField, \
      PasswordField, IntegerField, FieldList, FormField, validators
  
  
  class LoginForm(Form):
      username = TextField('Username', [validators.Required()])
      password = PasswordField('Password', [validators.Required()])
      remember = BooleanField('Remember me')
  
  
  def login_form(rform):
      return LoginForm(rform)
  
  
  class RegisterForm(Form):
      username = TextField('Username', [validators.Required()])
      password = PasswordField('Password', [validators.Required(),
                                            validators.Length(min=5, message='Password too short.'),
                                            validators.EqualTo('password_retype', message='Passwords must match.')])
      password_retype = PasswordField('Password (verification)', [validators.Required()])
      email = TextField('E-Mail', [validators.Optional(), validators.Email()])
  
  
  def register_form(rform):
      return RegisterForm(rform)
  
new_contents: from wtforms import Form, SubmitField, BooleanField, TextField, SelectField, \
      PasswordField, IntegerField, FieldList, FormField, validators
  
  
  class LoginForm(Form):
      username = TextField('Username', [validators.Required()])
      password = PasswordField('Password', [validators.Required()])
      remember = BooleanField('Remember me')
  
  
  def login_form(rform):
      return LoginForm(rform)
  
  
  class RegisterForm(Form):
      username = TextField('Username', [validators.Required()])
      password = PasswordField('Password', [validators.Required(),
                                            validators.Length(min=5, message='Password too short.'),
                                            validators.EqualTo('password_retype', message='Passwords must match.')])
      password_retype = PasswordField('Password (verification)', [validators.Required()])
      email = TextField('E-Mail (optional)', [validators.Optional(), validators.Email()])
  
  
  def register_form(rform):
      return RegisterForm(rform)
  
subject: Make it clear that the E-Mail address is optional.