diff --git a/apps/news/models.py b/apps/news/models.py
index 7c585148..24c5df11 100644
--- a/apps/news/models.py
+++ b/apps/news/models.py
@@ -361,6 +361,8 @@ class News(GalleryMixin, BaseAttributes, TranslatedFieldsMixin, HasTagsMixin,
 
     def create_duplicate(self, new_country, view_count_model):
         country_codes = list(Country.objects.all().values_list('code', flat=True))
+
+        # Get all existed slugs
         all_slugs = {slug_value
                      for slug_dict in News.objects.all().values_list('slugs', flat=True)
                      for slug_value in slug_dict.values()}
@@ -368,12 +370,17 @@ class News(GalleryMixin, BaseAttributes, TranslatedFieldsMixin, HasTagsMixin,
         new_slugs = {}
         for locale, raw_slug in self.slugs.items():
             slug = NewsSlug.parse(raw_slug, country_codes)
+
+            # all slugs LIKE% slug
             similar_slugs = sorted(x for x in all_slugs if NewsSlug.parse(x, country_codes).value == slug.value)
+
             if len(similar_slugs) == 0:
                 # It is impossible because at least current instance has slug
                 raise ValueError('Duplicating unsaved object')
             else:
+                # The last slug in similar_slugs is slug with largest count
                 last_slug = NewsSlug.parse(similar_slugs[-1], country_codes)
+
                 new_slug = NewsSlug(slug.value, new_country.code, last_slug.count)
                 if last_slug.country_code is not None:
                     new_slug.count += 1
diff --git a/apps/utils/parsers.py b/apps/utils/parsers.py
index 073aa1e4..dc84a60e 100644
--- a/apps/utils/parsers.py
+++ b/apps/utils/parsers.py
@@ -12,13 +12,19 @@ class NewsSlug:
         instance = NewsSlug()
 
         if len(rest) >= 1 and rest[-1] in country_codes:
+            # It is like 'slug-en'
+
             instance.value = '-'.join([slug, *rest[:-1]])
             instance.country_code = rest[-1]
         elif len(rest) >= 2 and rest[-1].isdigit() and rest[-2] in country_codes:
+            # It is like 'slug-en-1'
+
             instance.value = '-'.join([slug, *rest[:-2]])
             instance.country_code = rest[-2]
             instance.count = int(rest[-1])
         else:
+            # It is like 'slug'
+
             instance.value = '-'.join([slug, *rest])
 
         return instance