Apple's guideline on when to use modal vs pushed view controller upon tapping a table view cell seems confusing.
Take Settings->Twitter for example. If you tap Add Account cell, the view is pushed in for you to sign in. If you click on an existing Account, a modal view is shown instead. In most other places in Settings, pushed view is used instead. In Contacts' Edit mode, modal is used instead. I can't find a common pattern on when to use which.
What's Apple's Guideline on when to use modal vs pushed view controller when tapping a table view cell?