old_contents: from django.db import models
  from django.utils.translation import ugettext_lazy as _
  
  
  class AbstractSellingPoint(models.Model):
      text = models.CharField(_("Text"), max_length=255)
      product = models.ForeignKey('Product', related_name='selling_points')
  
      class Meta:
          abstract = True
          verbose_name = _("Selling point")
          verbose_name_plural = _("Selling points")
  
      def __unicode__(self):
          return self.text
  
  
  class AbstractWashingInstruction(models.Model):
      icon = models.ImageField(verbose_name=_("Icon"), upload_to='laundry_symbols/', blank=True)
      text = models.CharField(_("Text"), max_length=255)
  
      class Meta:
          abstract = True
          verbose_name = _("Washing instruction")
          verbose_name_plural = _("Washing instructions")
  
      def __unicode__(self):
          return self.text
  
      def render_icon(self):
          if self.icon:
              return '<img src="%s" alt="%s" title="%s">' % (self.icon.url, self.text, self.text)
          else:
              return None
      render_icon.allow_tags = True
      render_icon.short_description = _("Icon")
  
  
new_contents: from django.db import models
  from django.utils.translation import ugettext_lazy as _
  
  
  class AbstractSellingPoint(models.Model):
      text = models.CharField(_("Text"), max_length=255)
      product = models.ForeignKey('Product', related_name='selling_points')
  
      class Meta:
          abstract = True
          verbose_name = _("Selling point")
          verbose_name_plural = _("Selling points")
  
      def __unicode__(self):
          return self.text
  
  
  class AbstractWashingInstruction(models.Model):
      icon = models.ImageField(verbose_name=_("Icon"), upload_to='laundry_symbols/', blank=True)
      text = models.CharField(_("Text"), max_length=255)
  
      class Meta:
          abstract = True
          verbose_name = _("Washing instruction")
          verbose_name_plural = _("Washing instructions")
  
      def __unicode__(self):
          return self.text
  
      def render_icon(self):
          if self.icon:
              return '<img src="%s" alt="%s" title="%s">' % (self.icon.url, self.text, self.text)
          else:
              return None
      render_icon.allow_tags = True
      render_icon.short_description = _("Icon")
  
  
  class AbstractProductWashingInstruction(models.Model):
      washing_instruction = models.ForeignKey('WashingInstruction')
      product = models.ForeignKey('Product', related_name='washing_instructions')
  
      class Meta:
          abstract = True
          verbose_name = _("Product washing instruction")
          verbose_name_plural = _("Product washing instructions")
  
      def __unicode__(self):
          return unicode(self.washing_instruction)
  
  
subject: add AbstractProductWashingInstruction