Slight update to docs.

docs/src/files.md

@@ -21,20 +21,23 @@ the record is also written to the file, encoded in *record markers* which
 preceed and follow the record. Unfortunately, Fortran compilers have used
 various ways to encode the record markers (the following is from personal
 recollection and may be incorrect):
-* G77 used 4 bytes, so that records could be no longer than 2 GiB.
-* Ifort uses 4 bytes, and uses the sign bit to signal that more data will follow.
+* g77 used 4 bytes, so that records could be no longer than 2 GiB.
+* ifort uses 4 bytes, and uses the sign bit to signal that more data will follow.
   That is, the record is split into *subrecords*, where each subrecord has its
-  own record markers. For records smaller than 2 GiB, this is compatible to G77.
-* Gfortran 4.0 and 4.1 offered 8-byte record markers as an alternative to
-  G77-style record markers, and used them by default (at least on 64-bit systems).
-* Gfortran 4.2 introduced Ifort-compatible record markers. These are now
+  own record markers. For records smaller than 2 GiB, this is compatible to g77.
+* gfortran 4.0 and 4.1 offered 8-byte record markers as an alternative to
+  g77-style record markers, and used them by default (at least on 64-bit systems).
+* gfortran 4.2 introduced ifort-compatible record markers. These are now
   the default.
 All these kinds of record markers are supported by this package.
 
 In direct access mode, all records have the same, fixed size. This record size
 must be specified when opening the file. Records can be accessed in random
 order, by specifying the number of the record to be read/written in each
-`READ` or `WRITE` statement.
+`READ` or `WRITE` statement.  Currently it is assumed that records are stored
+in the file without any header or record marker.  This is compatible with the
+standard behaviour of gfortran and ifort.
+
 
 
 ## Opening files