Recently, while working on a webpart that mimicked functionality provided for SharePoint News Articles, I came across several issues where solutions were either barely documented or non-existent. After several hours of Googling, troubleshooting, reverse engineering, and guessing I found discovered various obscure solutions to all my problems.
The SharePoint REST API support for folders is limited. The support that is there is tailored to work with documents in document libraries. Because of this I see lots of questions on how to use the REST API to perform operations on lists with folders. My suggestion is... don't. The Client Object Model has full support for folders so I strongly suggest that you use it instead.
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