Today I realized that we have two tags for the same flag: z_flag and z-flag. This is causing the images with that flag to get divided, and it's not the easiest thing to notice when the tags differ at the second character.
How should I resolve this? "z_flag" seems to be the correct spelling and is more commonly used in tagging; should I retag the "z-flag" posts accordingly (since they're few enough to do manually), and then ask for a "z-flag" -> "z_flag" alias?