Advice on editing submissions to Alamy?

[bcrawford]

Is there anyone out there who has worked with Alamy and is able to give me some advice on editing my digital submissions? In reading the image spec requirements, they expect us to edit our own stuff, but also warn that they will reject overmanipulated images. So my question is....what types of modifications are okay and what will render my photos unacceptable? I appreciate any suggestions....Thanks!