Create a document in Microsoft Word and type "147th" with no space between the 147 and the th. It will automatically superscript the th. Now type "147 th" with a space between the 147 and the th. It will not superscript the th. If you look at the letters both forms occur and they are consistent with what Microsoft Word does. When there is no space, the th is superscript. When there is a space, the th is not superscript. These memos were written in Microsoft Word.
Here's the lost memo that Dan didn't release: