If you want to make something just for yourself then you can spell things the way you want. When create something for the public to see, you want to get everything as correct as you can because it is a reflection on you and your ability. It is just like a resume. If you make a resume with a lot of errors no one who has a good job is going to hire you. If you want to screw yourself then do crappy work and see where it gets you.
