Per discussion in the comments of SERVER-17975, in MongoDB systems since at least 2.6, one can use findAndModify with a "w:majority" write concern to perform a read of data that cannot be rolled back and is not stale. We should document this technique for users that require it.

Highlights of the technique:

1. The findAndModify must use exact match satisfiable with an existing unique index.
2. The findAndModify must modify some field in the document. I recommend using $inc to increment a field with a name like {{ _dummy_counter_}}.
3. The write concern used with the findAndModify must be w:majority

Caveats: Not all drivers support findAndModify with write concern.