You can use flags to pick (Flag as Pick) or reject (Flag as Reject) images. You can also clear flags that you assign (Clear Flag). Flagging is a great way to quickly assess images. You can also use flags to mark images that you are in the process of editing or you can flag several images with similar content so you can quickly select and compare them when trying to select the best version.

You can flag a file or version as reject to help you keep your catalog free of out of focus or otherwise poor quality images. One workflow would be to scan through new images, flagging the poor quality images as Reject. After all images have been reviewed, use the filter to show only the rejected images to verify that you marked only the poor quality images, then permanently delete the Reject images. You can also keep images that you flag as Reject — after they are flagged as Reject, they do not show up in the standard view of your Catalog, while leaving them on your computer just in case you do need that image later.