Bypassing authentication for channels in CMS channel manager
Through HST configuration in the repository you can force authentication for visitors accessing a channel or some specific sitemapitem for a channel. This is described at Authentication and Authorization Support. A worked out example of how you can force authentication and authorization on a specific sitemapitem is described at How to limit read access for different site visitors.
Now, typically however, you do not want to burden CMS authors / editors / webmasters that want to preview a document in the channel manager with a possible available channel authentication. A logged in CMS user you want to typically be able to bypass authentication for previewing documents in the channel manager. Bypassing authentication is supported by the hst:hosts configuration property hst:channelmanagersiteauthenticationskipped.
Configuring channel manager to bypass authentication for previewing channels is done through configuring:
+ hst:hst + hst:hosts - hst:channelmanagersiteauthenticationskipped = true