Inmate Photos

What are the rules for sending a photo to an internal Department of Oklahoma?

A friend of mine said he sent a completely normal a friend of hers who happens to be spending some time in prison McCalester and sent him back. So we wonder if there are any rules or guidelines that go when you send a photo of a prisoner

As far as I could find, innmates can get pictures (but not be sent unless approved). You can go here for Oklahoma DOC rules for http://www.doc.state.ok.us/Offtech/op030117.htm mail. The site says the photos may not contain gang-related activity or symbols. You can call 918-423-4700 to speak with someone in jail for making a more specific question. If there are specific rules about photos, not I can find online. (By the way, it was sent back to the prison administration to send it again?)