I'm not really sure what my online check in accomplished, as she reviewed every document, and ended up printing us identical boarding passes to the ones that I had printed the previous evening. When reviewing our passports, she asked where are Thai visas were. I pointed to them in the book. She said that the visa stamp doesn't say Thailand on it. It does have Thai writing as well as English which identifies the province issuing it. I did not see at the time that my re-entry permit, directly below the visa, does in fact. have the word "Thailand" in it.
This is the first time that we have ever had this issue before. Tim was busy putting jackets in the suitcase, so I looked at the Delta employee and asked her if she read Thai. I told her that the Thai writing above the visa was the Thai word for Thailand. That seemed to mollify her.