If you open the file type editor, and select a file type (doesn't matter which one), and then open the Info Tip tab, under the Insert Field->File Size entry, the 'Size (bytes)' entry is listed twice. Both are written in the same case, so what is the difference between these two entries?
Similarly, 'Description' is listed twice under Insert Field->General, so another apparently duplicated entry.
Thanks for noticing this. It has been fixed for the next beta.
The duplicate items are actually Folder Size and Folder Contents, which are also available at the top-level of the same menu. They weren't supposed to be in the categories sub-menus at all, and had the wrong labels assigned (the labels weren't meant to be used, but a change in the earlier betas resulted in them being used unexpectedly).