=item * Version
-This is four bytes containing the header version. This lets the header change over time.
+This is four bytes containing the file version. This lets the file format change over time.
+
+=item * Constants
+
+These are the file-wide constants that determine how the file is laid out.
+They can only be set upon file creation.
=item * Transaction information
The current running transactions are stored here, as is the next transaction
ID.
-=item * Constants
+=item * Freespace information
-These are the file-wide constants that determine how the file is laid out.
-They can only be set upon file creation.
+Pointers into the next free sectors of the various sector sizes (Index,
+Bucketlist, and Data) are stored here.
=back