[Answered ]-How to make reverse URL to current instance of application?

You can include myapp.urls twice, using the same application namespace, but a different instance namespace:

url(r'^myapp_1/', include('myapp.urls', namespace='myapp1', app_name='myapp')),
url(r'^myapp_2/', include('myapp.urls', namespace='myapp2', app_name='myapp')),

Then, in your code, reverse the url using the application namespace, and pass the current instance namespace in the current_app parameter:

reverse('myapp:rev', current_app=request.resolver_match.namespace)

When using the {% url %} tag in a template, you cannot pass the current namespace directly, but you can set the current_app attribute on the request for the same effect:

# in your view
request.current_app = request.resolver_match.namespace

# in your template
{% url 'myapp:rev' %}

In 1.9, this has slightly changed. You specify the app_name in the included url configuration, and the namespace in the call to include(), like this:

mysite/urls.py:

url(r'^myapp_1/', include('myapp.urls', namespace='myapp1')),
url(r'^myapp_2/', include('myapp.urls', namespace='myapp2')),

myapp/urls.py:

app_name = 'myapp'
urlpatterns = [
    url('^rev/$', views.rev, name='rev'),
]

Another change in 1.9 is that the {% url %} template tag now uses the namespace of the current request by default. If you need to reverse an url in the same namespace, you no longer have to set request.current_app explicitly. You still need to pass the current app if you use reverse().