Force.com Sites Guest User Profile Permissions

I’m working on an event registration application for the Sites Developer Challenge, and it involves a validation that the registrant’s email exists in a Contact record. Remembering that Steve Andersen had run into some obstacles with Contact.Email visibility, I decided to check the guest profile for Contact Field Level Security. Here’s what I found:

Guest profile Contact Field Level Security

If you squint a bit, you can see that the Opt-Out and Email fields are hidden to the guest user. I have no idea why these, in particular, are hidden. Likewise, I couldn’t find a pattern in which fields were shown on the custom objects I had created, nor which were visible on standard objects.

In any event, I don’t have any pearls of wisdom on this topic; this is more of an informative note to all that are using Sites (especially if you plan to do any communication-subscriptions) to check out the Field-Level Security.

For those wondering how to get to this Profile (since it is not visible in the usual Profile section), go to the Sites page > Site Name or URL > Public Access Settings (a button).