Organization of .NET Solutions and .NET Projects

With respect to the Design Pattern Framework, how does one know what goes in the Framework Project versus other Projects. 
I seeEncryption, Log and Transactions go into the general Framework folder because it is not specific to the website objects but how come Cart went into Framework Project?

Thanks

As you mentioned the Framework Project is a 'Utilities' type project, where generally applicable code resides, such as Encryption, Logging, etc. But it also contains the shopping Cart which is used (as a utility) by all Presentation Layers (UIs).  

In our current implementation the shopping cart is not persistent. If it were, then the Cart would be a Business Object and it would have certainly ended up in the Business Layer.

I hope this helps.