Apple Rejection - User generated content

•    14.3 - Apps that display user generated content must include a method for filtering objectionable material, a mechanism for users to flag offensive content, and the ability to block abusive users from the service

14.3 Details
Your app enables the display of user-generated content but does not have the required precautions in place.

Next Steps
It is necessary that you put all of the following precautions in place:
- Require that users agree to terms (EULA) and these terms must make it clear that there is no tolerance for objectionable content
- Use moderators to flag and remove inappropriate content and offensive users
- Users need a mechanism to flag objectionable content and report users generating this content
- Users need a mechanism to block abusive users
- Developer must act on objectionable content reports within 24 hours by removing the content and ejecting the user who provided the offending content
- Developer needs a method for ejecting users who violate the terms of the EULA

This message is most likely related to one of these 2 features:

- The Chat extension, because the users have the possibility to chat with one another, and to show public contents on their profile (description and profile picture, for instance). 
Apple requires that precautions are put in place in order to flag and block users who would publish offensive or inappropriate content in a message or on their profile. 

- The Submission page, because users have the possibility to send content that will be later on published into the app.
Although this content is not published in the submit page itself, and needs to be moderated (as it cannot be published into the app without any intervention from you, see the online help about The Submission page) Apple still requires that any user of the app can flag offensive content that would be published in the Submit page. 

- Require that users agree to terms (EULA) and these terms must make it clear that there is no tolerance for objectionable content

To have your users check a box and accept the general terms of use of your app on the first time they sign up, you need to add the property shouldAcceptTerms = 1 in the API Settings of your back office. 

Click here for the tutorial on how to do it.

- Use moderators to flag and remove inappropriate content and offensive users

The developer of the app receives a notification for every new content or comment posted into the app.
He has to moderate this content prior to its publication into the app, the content cannot be published in the app without him moderating it.

- Users need a mechanism to flag objectionable content and report users generating this content

Answer Apple that any user can flag an offensive user directly from the user's profile, and report objectionable content to the developer, and provide them your own screenshot.
To do so, select a user profile in the users' directory page of your app, and do as if you were sending this user a message. The warning sign will show on the top right of the page, hit it to show the warning message like on the image below.

You can also create a form (see the online help about The form page) so your users can report any offensive content in your app.
We recommend you give it an explicit name such as "Report inappropriate content". 

- Users need a mechanism to block abusive users

Answer Apple that the Chat page already provides this possibility (see the online help about the Chat extension) and send them a screenshot that proves it.  
To take your own screenshot for Apple, go to the Chat page of your app and select a conversation you have with another user. 
Do as if you were going to block this user and take your screenshot. 

- Developer must act on objectionable content reports within 24 hours by removing the content and ejecting the user who provided the offending content

- Developer needs a method for ejecting users who violate the terms of the EULA 

Answer to Apple that the developer has full control on the app and can remove a content or a user at any moment. 
He will take actions to remove any inappropriate content within 24 hours, and delete the user who provided it from the app users list. 

In order for users to flag and report offensive content, you have 2 possibilities here: 

1/ Create a Form page so your users can report an abuse. 

2/ Customize the Text field of your Submission page in order for users to report an abuse from there.
Click here for the tutorial on how to do it.

Answer Apple after doing the necessary in your back office.