title: What's the point of using namespace inside include? (Django 2.0)
body: <p>What's the point of using namespace inside include, if adding app_name in the app's urls is the one that actually lets me use the "app:view" syntax.</p>
  
  <h2>Blog_app/urls.py</h2>
  
  <pre><code>from django.urls import path
      from django.views.generic.base import RedirectView
      from . import views
  
      app_name = 'posts'  #APP_NAME
  
      urlpatterns = [
             path('',RedirectView.as_view(url='posts/'), name='home'),
             path('posts/',views.post_list, name='list'),
             path('posts/detail/&lt;int:pk&gt;',views.post_detail, name='detail'),
             path('posts/delete',views.post_delete, name='delete'),
             path('posts/create',views.post_create, name='create'),
             path('posts/update',views.post_update, name='update'),]
  </code></pre>
  
  <h2>Project/urls.py</h2>
  
  <pre><code>from django.contrib import admin
  from django.urls import path,include
  
  urlpatterns = [
      path('admin/', admin.site.urls),
      path('', include('blog_app.urls',namespace='posts')),]
  </code></pre>
  
  <p>this code works for reversing the url to posts/detail like this</p>
  
  <h2>example.html</h2>
  
  <pre><code>&lt;a href="{% url 'posts:list' %}"&gt; Example &lt;a/&gt;
  </code></pre>
  
  <p>but if delete the namespace it stills reverses my url to posts/detail</p>
  
  <h2>Project/urls.py</h2>
  
  <pre><code>from django.contrib import admin
  from django.urls import path,include
  
  urlpatterns = [
      path('admin/', admin.site.urls),
      path('', include('blog_app.urls')), #NAMESPACE DELETED
  
  ]
  </code></pre>