The tag fairy (that wonderful, glorious, mysterious creature!! LOL) is responsible for the descriptors underneath some people's log-in names on their posts. You can change your own tag to say something different than "DIS Veteran", but it won't be in color; only the tag fairies can add the color. The tag fairies usually choose something you mentioned in a post somewhere along the line and make that a "tag" for you.
(as you can see, I had to resort to bribery -- but hey, it worked!! LOL)