add remark about different byte sequence

Author: alinpahontu2912

xml/System.IO.Compression/DeflateStream.xml

@@ -64,6 +64,8 @@ The <xref:System.IO.Compression.DeflateStream> class uses the same compression a
 
 The compression functionality in <xref:System.IO.Compression.DeflateStream> and <xref:System.IO.Compression.GZipStream> is exposed as a stream. Data is read on a byte-by-byte basis, so it is not possible to perform multiple passes to determine the best method for compressing entire files or large blocks of data. The <xref:System.IO.Compression.DeflateStream> and <xref:System.IO.Compression.GZipStream> classes are best used on uncompressed sources of data. If the source data is already compressed, using these classes may actually increase the size of the stream.
 
+The exact compressed byte sequence returned by <xref:System.IO.Compression.DeflateStream> can vary between .NET releases, platforms, or underlying compression engines, as changes in zlib versions, algorithm tweaks, or performance optimizations may produce different outputs for the same input data, but any data compressed by DeflateStream can always be decompressed to its original form without loss.
+
 ## Examples
 
 The following example shows how to use the <xref:System.IO.Compression.DeflateStream> class to compress and decompress a file.