I'm very new to houdini, and I'm having trouble understanding how to create special attributes and groups in my digital asset. I've been searching the docs and doing google searches, but I can't seem to find information on this topic.

This is the link to the docs:
http://www.sidefx.com/docs/unreal/_attributes.html [www.sidefx.com]

Can someone help me or point me towards some good examples?

Thank you in advance :-)