A headstone image becomes a record after it is approved through the rating process. Red flags are a way to rate images. Here is what they are for and how to use them.
BillionGraves website:
#1 Log in to BillionGraves.
#2 Hover over Volunteer (main menu).
#3 Click Transcribe.
Rate image:
#1 Click the Rate Image Quality 
#2 Select the correct option from the dropdown list.
Change image classification:
#1 Click the Rate Image Quality 
#2 Click Cemetery Gate or Property (Not a headstone).
#3 Click OK in the popup box to reclassify the image as cemetery media.
Step 2 & 3
Rate An Image
Step #1 & 2
Examples of Image Quality
The Photo is Good- This can be used in an individual's album when a photo has been placed in the "reported Images" file. Sometimes well meaning individuals will flag photos that shouldn't be flagged. In order to remove it from your reported images file, please mark it as the "Photo is Good" to remove it from reported images.
Good Photo Examples-
Although this one is harder to read, it is still a good photo.
The photo is Blurred- This should only be used if the photo is so blurry you are unable to read what is on the stone, or determine if it is a stone at all. If the stone is readable, but a litte blurry, please transcribe it, as it will give people an incentive to replace it.
Blurry, Fuzzy Example