TYPO3 Core

doc_core_api

$TCA array reference -> ['columns'][fieldname]['config'] / TYPE: "group" -> internal_type

- There are two options for a value:

+ There are four options for a value:

+ 2. "file_reference" - this will create a field where local files can be referenced. In contrast to "file" referenced files (usually from fileadmin/) will not be copied to upload folder.