It's just a word used by idiotic metalheads who like to look down on those who listen to metal bands commonly associated with Hot Topic. Trust me, I used to be one of them. 1). What is mallcore? Basically mallcore entails pop metal (such as newer In Flames, Dead By April, Scar Symmetry), nu-metal (Slipknot and Korn in particular) and other bands such as System of a Down, Rammstein and Tool. 2.) How is one mallcore? One is mallcore if they happen to listen to these bands and follow said trends set by stores in the mall that sell merch by these bands. 3). What isn't mallcore? Black metal and death metal that's not pushed in the mall. 4). How is it not mallcore? Because it's not found in your local Hot Topic. 5). Where is mallcore found? Browse through the CD section of Hot Topic. God, I hate elitists. People like what they like. On a more serious note, if you're bothered by people calling bands you like "mallcore" then you're probably thinking into it too much. It's a completely stupid term for all the reasons I just said above. We all have our likes and dislikes, but looking down on stuff just because it's played on the radio or more mainstream than something else is the height of idiocy. It makes me wonder if people actually appreciate music anymore or are just looking to be more "cool, edgy and underground" than their friends.