Category # 07
Once you pass the Core exam, you have one year to take and pass the category exam.
Here is a web link to the reference: http://www.pacode.com/secure/data/007/chapter128/s128.43.html See section 128.43 (d).
The entire regulation can be found here: http://www.pacode.com/secure/data/007/chapter128/chap128toc.html.
I hope this answers your question.