A combination of hardcore and hipster. Hipstercore people normally wear tight pants, band t-shirts, lots of make-up (for girls), and lots of contrasting colors, like neon green and black. They listen to a wide range of music that includes alternative rock, screamo, post-hardcore, punk-pop, heavy metal, classic rock, punk-rock, and techno. They tend to be anti-mainstream, just like regular hipsters, and they LOVE triangles.
Don't ever called someone who's hipstercore "ironic" because they hate that. Most of them think of themselves as just pretty chill people who like cats.
Joe: Wow! Look at Melissa's tight pants and kitty cat t-shirt!
Sarah: It's her extremely dark makeup that really pulls the whole thing together.
Melissa: Thanks, guys. Do you want to go to an Aquabat's concert?
Joe&Sarah: YOU'RE SO HIPSTERCORE!