Gang culture is ever-evolving, and according to Business Insider, one of the things that's changed is the dress code. In the 1980s and '90s, Crips members were expected to dress all in blue, but in more recent decades, that's changed for a very practical reason: It's easier to avoid attracting unwanted attention from law enforcement when your affiliation isn't on view for all to see.

The change was observed as early as 1988, when The New York Times reported that Crips who were moving into new territories were forgoing the traditional colors.

Colors remained important, though, and according to materials seized from a United Gangsta Crips member by the New York City Police Department, there were still colors that were off-limits. Red is forbidden, as it's associated with the Bloods, as was yellow, for an association with the Latin Kings. Members are required to know the meanings behind acceptable colors: They wear blue to signify their roles as soldiers, black for gangsters, purple for war, and green for money.

That's pretty straightforward, and more difficult are the code words and numbers gang members are required to learn. Those change regularly and are used to refer to things like weapons, locations, other gangs, and orders. The so-called "hand stacks," or hand gestures, are also required: They facilitate private communication in public spaces. Their meanings can regularly change, too.

ncG1vNJzZmivp6x7qL7Up56eZpOkunCCl2pqb3Ffp8KtsdJmmquhoKh6qa3VnmStp12bvK24zrBm