--- a/Orthanc/Core/Enumerations.h	Fri Aug 07 21:25:10 2015 +0200
+++ b/Orthanc/Core/Enumerations.h	Thu Aug 13 12:52:51 2015 +0200
@@ -239,6 +239,15 @@
   };
 
 
+  // https://en.wikipedia.org/wiki/HTTP_compression
+  enum HttpCompression
+  {
+    HttpCompression_None,
+    HttpCompression_Deflate,
+    HttpCompression_Gzip
+  };
+
+
   // http://www.dabsoft.ch/dicom/3/C.12.1.1.2/
   enum Encoding
   {
@@ -300,8 +309,23 @@
 
   enum CompressionType
   {
+    /**
+     * Buffer/file that is stored as-is, in a raw fashion, without
+     * compression.
+     **/
     CompressionType_None = 1,
-    CompressionType_Zlib = 2
+
+    /**
+     * Buffer that is compressed using the "deflate" algorithm (RFC
+     * 1951), wrapped inside the zlib data format (RFC 1950), prefixed
+     * with a "uint64_t" (8 bytes) that encodes the size of the
+     * uncompressed buffer. If the compressed buffer is empty, its
+     * represents an empty uncompressed buffer. This format is
+     * internal to Orthanc. If the 8 first bytes are skipped AND the
+     * buffer is non-empty, the buffer is compatible with the
+     * "deflate" HTTP compression.
+     **/
+    CompressionType_ZlibWithSize = 2
   };
 
   enum FileContentType