You will need your sun glasses for this one!
StyleOverridesID shows where the user has set an attribute not in the style sheet.
This is particularly useful when preparing documents for EPUB.
Bold View above.
Red is showing the override on the paragraph and yellow is showing character overrides.
The Line View (above) is softer on the eye.
You can show or hide paragraph / character attributes independently.
If you have the StyleOverrides showing on screen and choose to print to interactive pdf you will see the overrides marked in the PDF.
Currently available for InDesign CS 5, 5.5 and 6.
If you don't like bold or line view custom drawing modules can be ordered.
To buy StyleOverrides go here.