That's a CB Gallery language string where Type can be Photo, Video, Music, or File. Those language strings also have type specific keys you can use. Example as follows.
Generic key: ARE_YOU_SURE_DELETE_TYPE
Specific key: ARE_YOU_SURE_DELETE_PHOTOS
There's a specific key for each stored type as follows ARE_YOU_SURE_DELETE_VIDEOS, ARE_YOU_SURE_DELETE_MUSIC, and ARE_YOU_SURE_DELETE_FILES. Using the specific key you'd have more control over the structure of the string if the generic key doesn't work for your language.