the study of flags.
vex·il·log·ic [vek-sil-loj-ik] vex·il·lo·log·i·cal, adjective
A vexillographer is one who designs flags. If you're a vexillologist, you study flags.
Flags are a unique method of communication. They represent people, governments, agencies, multi-national groups, families, and more.
Flags are, by necessity, intended to be recognized from great distances. They carry unique elements of design that are meant to identify the organization, people or government that they represent.
In North America, the study of flags is lead by the North American Vexillological Association (NAVA). Their website is rich with information about flags, and if you are interested in this field, you are encouraged to check them out.
One article that might be of particular interest to someone interested in good flag design is NAVA's "Good Flag, Bad Flag." This article offers great insight to the standards by which great flag design should be judged.
Click here: Good Flag, Bad Flag