The best I can do with vexillology is give a URL to a flag site:
http://www.nava.org/ Lots of information there.

In my high school Latin class we learned the Pledge of Allegiance in Latin. I used to know it by heart, but now can't remember much of it. I do recall vexillo, though.

Once, years later, when doing a crossword puzzle, "vexillologist" was one of the clues, and I amazed my sister by stating "it has something to do with the study of flags."

Ah, the advantages of studying Latin.

I studied Latin for a year, formally, and then went on to speak fluently a Latin language; still this is the first time I've heard this word. I am truly vexed.

Which no doubt vexed your sister.

this is 'trific vexillological site
http://www.fotw.net/flags/index.html
jj