Accessing system content
Some of the contents in sensenet (e.g. SystemFolder, SystemFile) - mostly because they were created for technical reasons - are system contents, that means they can be usually seen only for administrators and they are not the part of the OData query responses by default. The trash feature should be also mentioned here, because the content items moved to the trash are handled and behave like system contents, by default they are not returned in the results.
Autofilters is on, result list will not contain system or deleted content. For example content of a system folder will not be returned. If you want to see these content in the results, switch the filter off: