Stereotyping, the view from a teen

Firstly I feel I have to clarify that this isn't going to be a post about all forms of stereotyping but more the stereotypes that most teenagers these days use to address each other and class each other.
I have to start by coming true and saying that I use the stereotypes myself, but let me explain that to you. In my city there are what almost amount to factions of teenagers that go around in groups, act and look certain ways. Now in my case I use these stereotypes as a means of essentially identifying people in conversation, for example if a group of people are walking towards us or something I'll refer to them by the corresponding stereotype as a way to almost identify who I am talking about them to whomever I'm with. The fact is stereotypes are in fact now a part of modern vocabulary in a way as they're almost a fast-track way to identifying someone.
But is this wrong?
Now my personal view is that a stereotype is justified if it isn't used in an untoward manner, for example using a stereotype of someone to insult them would be wrong I.E going up to someone and shouting this at them. But if used in the manner of conversation with someone so they can gain an understanding of how they dress and act then I believe that is okay. Whether I'm wrong or not I don't know, but if I believed it was wrong I'd not be doing it.

I think it has reached the point where I have to explain to you the stereotypes I use, now the main one I guess everyone uses is Chav, now for me Chav is literally the way someone dresses aka the Tracksuit and also usually the way someone acts with the accent and how they act. Then there's the people called 'Greebs' now this one is a bit more complicated, it's essentially someone who poses as a skater but can't skate, they basically turn up and repeatedly fail a trick for hours and do the same daily. These are just two of the few I use, I must emphasize the fact I personally think within reason stereotypes such as those I have explained are okay. However racial stereotypes and the more serious use of stereotyping to offend people is not okay in my view and shouldn't be done. I think it's a fact of humanity that our brains always look to create stereotypes as a shortcut to almost like a fact file on what we know about that type of thing or person, this said I think we still are able to control and adapt how we think.