My tool oledump uses indicators, you're probably most familiar with indicators M and m that indicate that a stream contains macros.

Here is an overview of all possible indicators:

• M: Macro (attributes and code)
• m: macro (attributes without code)
• E: Error (code that throws an error when decompressed)
• !: Unusual macro (code without attributes)
• O: object (embedded file)
• .: storage
• R: root entry

If you want to know more, I recorded this video:

Didier Stevens
Senior handler
Microsoft MVP
blog.DidierStevens.com DidierStevensLabs.com