diff --git a/pst/src/main/java/io/github/jmcleodfoss/pst/BBTEntry.java b/pst/src/main/java/io/github/jmcleodfoss/pst/BBTEntry.java
index d2a78175..2eebdac3 100644
--- a/pst/src/main/java/io/github/jmcleodfoss/pst/BBTEntry.java
+++ b/pst/src/main/java/io/github/jmcleodfoss/pst/BBTEntry.java
@@ -7,44 +7,52 @@
 *	@see	io.github.jmcleodfoss.pst.PagedBTree
 *	@see	io.github.jmcleodfoss.pst.PagedBTree.BTEntry
 *	@see	<a href="https://docs.microsoft.com/en-us/openspecs/office_file_formats/ms-pst/53a4b926-8ac4-45c9-9c6d-8358d951dbcd">MS-PST Section 2.2.2.7.7.3: BBTEntry (Leaf BBT Entry)</a>
+*	@see	<a href="https://blog.mythicsoft.com/ost-2013-file-format-the-missing-documentation/">OST 2013 file format the missing documentation blog entry</a>
 */
 class BBTEntry implements BTreeLeaf
 {
 	private static final String nm_bref = "BREF";
 	private static final String nm_cb = "cb";
+	private static final String nm_cbInflated = "cbInflated";
 	private static final String nm_cRef = "cRef";
 
-	/**	The Unicode-specific fields in the input stream which make up the block B-tree leaf entry. */
-	private static final DataDefinition[] unicode_fields = {
-		new DataDefinition(nm_bref, DataType.brefUnicodeReader, true),
-	};
-
-	/**	The size in bytes of the Unicode-specific fields in a block B-tree leaf entry. */
-	private static final int UNICODE_SIZE = DataDefinition.size(unicode_fields);
-
-	/**	The ANSI-specific fields in the input stream which make up the block B-tree leaf entry. */
-	private static final DataDefinition[] ansi_fields = {
-		new DataDefinition(nm_bref, DataType.brefAnsiReader, true),
-	};
-
-	/**	The size in bytes of the Unicode-specific fields in a node B-tree leaf entry. */
-	private static final int ANSI_SIZE = DataDefinition.size(ansi_fields);
-
-	/**	The fields common to both ANSI and Unicode files in the input stream which make up the block B-tree leaf entry. */
-	private static final DataDefinition[] common_fields = {
-		new DataDefinition(nm_cb, DataType.integer16Reader, true),
-		new DataDefinition(nm_cRef, DataType.integer16Reader, true)
+	/**	The fields in the input stream which make up the block B-tree leaf entry, which are different depending on the file format type.
+	*	@see	<a href="https://docs.microsoft.com/en-us/openspecs/office_file_formats/ms-pst/53a4b926-8ac4-45c9-9c6d-8358d951dbcd">MS-PST Section 2.2.2.7.7.3: BBTEntry (Leaf BBT Entry)</a>
+	*	@see	<a href="https://blog.mythicsoft.com/ost-2013-file-format-the-missing-documentation/">OST 2013 file format the missing documentation blog entry</a>
+	*/
+	private static final DataDefinition fields[][] = {
+		/* ANSI fields and sizes */
+		{
+			new DataDefinition(nm_bref, DataType.brefAnsiReader, true),
+			new DataDefinition(nm_cb, DataType.integer16Reader, true),
+			new DataDefinition(nm_cRef, DataType.integer16Reader, true)
+		},
+
+		/* Unicode fields and sizes */
+		{
+			new DataDefinition(nm_bref, DataType.brefUnicodeReader, true),
+			new DataDefinition(nm_cb, DataType.integer16Reader, true),
+			new DataDefinition(nm_cRef, DataType.integer16Reader, true)
+		},
+
+		/* OST 2013 fields and sizes */
+		{
+			new DataDefinition(nm_bref, DataType.brefUnicodeReader, true),
+			new DataDefinition(nm_cb, DataType.integer16Reader, true),
+			new DataDefinition(nm_cbInflated, DataType.integer16Reader, true),
+			new DataDefinition(nm_cRef, DataType.integer16Reader, true)
+		}
 	};
 
-	/**	The size in bytes of the fields common to ANSI and Unicode files in a block B-tree leaf entry. */
-	private static final int COMMON_SIZE = DataDefinition.size(common_fields);
-
 	/**	The block reference for this block of the B-tree. */
 	final BREF bref;
 
 	/**	The number of raw data bytes in the block. */
 	final int numBytes;
 
+	/**	The total number of data bytes in the block accounting for compression. */
+	final int totalBytes;
+
 	/**	The reference count of the block. */
 	private final int refCount;
 
@@ -58,9 +66,10 @@ class BBTEntry implements BTreeLeaf
 		java.io.IOException
 	{
 		DataContainer dc = new DataContainer();
-		dc.read(entryStream, context.unicode() ? unicode_fields : ansi_fields, common_fields);
+		dc.read(entryStream, fields[context.pstFile.header.fileFormat.index.getIndex()]);
 		bref = (BREF)dc.get(nm_bref);
 		numBytes = 0xffff & (Short)dc.get(nm_cb);
+		totalBytes = context.pstFile.header.fileFormat.index == FileFormat.Index.OST_2013 ? (0xffff & (Short)dc.get(nm_cbInflated)) : numBytes;
 		refCount = 0xffff & (Short)dc.get(nm_cRef);
 	}
 
@@ -70,7 +79,7 @@ class BBTEntry implements BTreeLeaf
 	*/
 	public int actualSize(final BTree.Context<BTree, BTreeLeaf> context)
 	{
-		return COMMON_SIZE + (context.unicode() ? UNICODE_SIZE : ANSI_SIZE);
+		return DataDefinition.size(fields[context.pstFile.header.fileFormat.index.getIndex()]);
 	}
 
 	/**	{@inheritDoc} */
@@ -116,6 +125,8 @@ public java.nio.ByteBuffer rawData(final BlockMap bbt, final PSTFile pstFile)
 	@Override
 	public String toString()
 	{
-		return String.format(bref.toString() + " bytes %d ref count %d", numBytes, refCount);
+		if (numBytes == totalBytes)
+			return String.format(bref.toString() + " bytes %d ref count %d", numBytes, refCount);
+		return String.format(bref.toString() + " bytes %d (total %d) ref count %d", numBytes, totalBytes, refCount);
 	}
 }