I was unable to find any resource listing ALL icons for Solution Explorer and/or Navigator explaining their meanings. I mean, for somebody new to that, seeing a square, a question mark, or a no entry sign, next to a file, is pretty obscure.
Any help much appreciated
Here is the link explained in MS document in details: http://msdn.microsoft.com/en-us/library/26k97dbc(v=vs.80).aspx
One thing turned me off in the VS 2010 Solution Explorer is, the dotted tree lines are missing. It makes the folder-file relationships very easy to identify. Without it like current VS 2010, you'll have to struggle to find out what folder a file belongs to.
If you mean the "Source Control Item Status" icons that appear next to files in the tree view.
See http://msdn.microsoft.com/en-us/library/ms181372(v=vs.80).aspx
Here's a list for the Solution Explorer/Class View/Object Browser icons : https://docs.microsoft.com/en-us/visualstudio/ide/class-view-and-object-browser-icons?view=vs-2017 (I know that this is a 7 year old question but that's what I came here looking for... not the SCC icons)
I also have not found a comprehensive list of the icons, but can at least report that that the "no entry" icon (red circle with a horizontal white bar) means that the file is not included in the project.
I've hit the strange case where the Properties Window says Included In Project True, but the Solution Explorer shows, correctly, that the file was not included in the project. (Moral: Trust the icon.) The fix was, in the Properties window, change Included In Project to False, and then back to True.