It can be the regulator.
http://www.pca.org/tech/tech_qa_question.asp?id={33336754-C0C0-49C4-9EB9-BD3218E4DAD1}
http://www.pca.org/tech/tech_qa_question.asp?id={33336754-C0C0-49C4-9EB9-BD3218E4DAD1}
Links do not want to work. So go to the PCA site, tech session, and search under regulator.