As I've become more familiar with WPG 2012, I'm learning about the "DATE TAKEN" field as shown in the program's "Tag and Caption" pane in the "Information" section at the bottom of that pane.

It's important to me to know when my work creating metadata for my files is stored in the actual file and not in some auxiliary form elsewhere.  I've noted that most often, when dealing with a JPG file that the date taken is stored in the EXIF area of the JPEG file.  However, WPG 2012 allows one to input a DATE TAKEN for AVI, MP4, BMP, MOV and other files.  However, there is no EXIF for these files.  So, apparently sometimes WPG is storing this metadata in its own proprietary format.  I've also found several JPEG files that were imported from older (1998 - 2003) vintage digital cameras where some sort of date was provided by the camera, but WPG decided to store this information elsewhere and not within the EXIF of the JPEG.

I'd like to know exactly when WPG stores metadata in and EXIF of a JPEG file, and when it stores is elsewhere, and where and in what format it stores it elsewhere.  Is it within its .PD6 file?

My other post about grey thumbnails seems to be related to this date issue.  As I discovered several JPG files with no EXIF date taken information (as revealed by Windows File Explorer), while these JPG files DID have a date taken shown in the WPG program, once I input a date taken in WFE, suddenly the grey thumbnail issue would correct within WPG!  Weird?  Why?  Who's in charge of thumbnails for WPG, the program itself, or WFE and the OS?

Thanks.