In some applications such as journaling, or when using very large files, you want to upload a file in chunks. You might have large files that time out during an upload, or fail because of a bad connection. You can use the CMIS 1.1 append parameter in these situations.
You can use the isLastChunk parameter to indicate to the server that the chunked data is complete. The following example puts a chunk of data to a specific existing Alfresco object:
http://localhost:8080/alfresco/api/-default-/public/cmis/versions/1.1/atom/content?id=915b2b00-7bf6-40bf-9a28-c780a75fbd68&append=true