-// On unix most filesystems support sparse files, so right now I'm just
-// assuming sparse file support on unix. On Windows it's possible to test, and
-// sparse files should be available on Win 5+ with NTFS.
+// On unix, most filesystems support sparse files, though not all. So for now
+// I'm not assuming sparse file support on unix. On Windows it's possible to
+// test, and sparse files should be available on Win 5+ with NTFS.