There are times you may need to be absolutely sure a value saved in your dropdown/radio field is one of the provided options.

If you are using custom code to generate a list of posts for selection, you can use this to show the post title or any other info from the post that was selected in your field. After adding this function, you can get any information from that post that you would like.
[25 show_post=post_title]
[25 show_post=post_name] (slug)