Add a new file using a multipart/form-data POST containing the file's metadata and the file contents. The metadata part includes required properties such as the name, format, and parentFolderId. Use the special keyword "root" to add files to the root folder of a teamsite. The content part includes the file's binary content to be uploaded.

Use an optional query string parameter resolveNameCollision=true to automatically append an index such as (1)(2)(3) etc. until a name is found which does not conflict with an existing document in the folder.