Excel Icon with Mysterious Black Shape on it

[Croms_Beard]

Hello all - I'm hoping you can answer a question for me.

First, the background:

I currently work in an enviroment where 3 versions of Excel are actively used: 2003, 2007 & 2010. The version I primarily use is 2007 (as it is the defualt version that opens files when I double-click on them).

Recently I was navigating a network drive searching for historical documentation/files that could help me with a project, and discovered many of the Excel file icons have an extremely small black square in the lower left-hand corner portion of the icon, with some sort of shape that resembles an octagon with a lightening bolt in the middle of it. It is very difficult to tell exactly what it is as it's extremely small, even in thumbnail view, and is very low res. I should also mention that many of these files are older with 12+ months since their create date/last modified date, and that other types of files (Word, Acrobat, etc.) are affected as well.

What is strange is that in the "Details" view of my explorer the file sizes of these files with the strange icons are listed, but when I double-click one of them to open, nothing happens at first...then the file size changes to '0 KB' from whatever it was before after a few seconds, then a blank file opens. Additionally the 'last modified' date changes to the date/time I tried to open it (which sort of freaks me out). No further messages are displayed.

Question: What does this icon represent - archived or corrupted files? Am I causing harm by trying to open them?

 

[L. Howard]

Does this help, I know nothing about the image you see...
I googled and got this:

I think you'll find that is a black clock. 
This means that the file has been archived to tape and will take a very long time to access. 
The black clock is sometimes seen even if your system is not equipped with Hierarchical Storage Management. When this happens, it's because some program (typically a setup program) didn't check error codes properly. 

CopyFileAttributes(LPCTSTR pszSrc, LPTSTR pszDst)
{
SetFileAttributes(pszDst, GetFileAttributes(pszSrc));
}

The above code fragment fails to check for an error code from GetFileAttributes. It so happens that GetFileAttributes fails by returning the value 0xFFFFFFFF. If you fail to check this error code, you end up setting every possible attribute on the destination, including FILE_ATTRIBUTE_OFFLINE. FILE_ATTRIBUTE_OFFLINE is the flag that tells Explorer that the file has been archived to tape. 

Standard overlay icons are: 

A small arrow: Shortcut icons have a small arrow in the lower-left corner. 
A small hand: Indicates a shared folder. 
A small blue arrow (downward-pointing): Files to be written to CD. 
A pair of blue swirling arrows: Offline folders. 
A small black clock: The file has been archived.

Regards,
Howard

 

[Croms_Beard]

Howard - the 'black clock' overlay icon makes sense - this helps! (I feel silly for not using 'overlay' in my prior searches). I will follow up with my IT folks.