Stop sign icon in VS2005 Express solution explorer

What does a small stop sign icon on a file in solution explorer mean? Someone asked the same question a year ago Original Question but the answer provided is of no help.

The icon looks like this:

Suffice to say that the sign is not one presented in the VS documentation and is a UK Stop sign (red circle with a white horizontal bar) not a US 开发者_JAVA技巧one.

The project is WebKit and the build process cannot find AuthenticationCF.h even though the file is present. I presume the sign might shed some light on this.

Thanks, Andy

Actually, that icon indicates that the file is not set to build for your configuration. Double check by right clicking and clicking properties on the file. You will notice (probably) that the first item, "exclude from build" is set to "yes". Set it to no and the icon will go away. Now, this doesn't address why it wasn't set to build and you might run into some issues getting it to build with the includes and libs you have for a certain project, but that is what the icon means.

From MSDN:

Represents an item that is not under Team Foundation version control because the user has explicitly excluded the item from version control.

Note:

The linked page is essentially the same one from the answer to the "original question", but simply the most up-to-date visual studio one.