There are four simple rules:
:star: #1: Credit me
:bulletblue: include my name and/or visible clickable link to my stock account or stock image
:star: #2: Let me know if you've used my stock
:bulletblue: send me a note or leave a comment to my main page or stock picture
:star: #3: Don't just slightly edit my pictures and then claim them as your own art. BE CREATIVE.
:star: #4: You're not allowed to redistribute my stock images in any way.
After you have provided proper credits and notified me of stock usage, you're allowed to:
:bulletblue: sell deviantART prints;
:bulletblue: use pictures containing my stock image