Including captions in app generated images

I am having a doubt regarding the Facebook policies. It is being stated that:

IV. Application Integration Points

.....

1. You must not pre-fill any of the fields associated with the following products, unless the user manually generated the content earlier in the workflow: Stream stories (user_message parameter for Facebook.streamPublish and FB.Connect.streamPublish, and message parameter for stream.publish), Photos (caption), Videos (description), Notes (title and content), Links (comment), and Jabber/XMPP.

..... Source: https://developers.facebook.com/policy/

And from the examples & explanation page, it says the following for Photos:

You must not pre-fill Photo captions unless the user manually generated the content earlier in the workflow. These fields are intended for users to express themselves. Pre-filling these fields erodes the authenticity of the user voice.

So, my question is: I have seen 99% of the apps (that I used), is auto-filling caption field for photos with say, something like: You can try it by visiting here: http://www.apps.blahblah.com/appname

Isn't that against the facebook policy ? Or they are not flagged because they are using the extended permissions(publish_stream) instead of the post_actions ?

If it is not allowed for both the permissions, then my next question is, how would we tell the users viewing the photo, the link to the app so that these audiences can also try the app ?

Also, if possible, I would like to see a small example of the caption that would be generated in the workflow as mentioned here in the policies: ...You must not pre-fill any of the fields associated with the following products, unless the user manually generated the content earlier in the workflow....

Thanks in advance.

It is against policies, but many apps do it nevertheless.

I think a compromise would be to have the user enter their own message, and then just append a little link to the end of that before posting it.

As for the example, what exactly would you like to know/see? You have the user put in a message through a text field/input box/whatever, and set that as the message while posting the image.