[svnbook] r4299 committed - * en/book/ch03-advanced-topics.xml...

[svnbook at googlecode.com]

Revision: 4299
Author:   cmpilato at gmail.com
Date:     Thu Sep  6 07:49:45 2012
Log:      * en/book/ch03-advanced-topics.xml
   Warn about the dangers of keyword substitution in binary file
   formats, and remove a parenthetical expression which could imply the
   reverse.
http://code.google.com/p/svnbook/source/detail?r=4299

Modified:
  /trunk/en/book/ch03-advanced-topics.xml

=======================================
--- /trunk/en/book/ch03-advanced-topics.xml	Thu Sep  6 07:34:45 2012
+++ /trunk/en/book/ch03-advanced-topics.xml	Thu Sep  6 07:49:45 2012
@@ -2382,8 +2382,14 @@
        performing substitutions into complex file formats that
        themselves use fixed-length fields for data, or for which the
        stored size of a given data field is overbearingly difficult to
-      modify from outside the format's native application (as is true
-      for the older Microsoft Office document formats).</para>
+      modify from outside the format's native application.  Of course,
+      where binary file formats are concerned, you must always take great
+      care that any keyword substitution you introduce—fixed-length
+      or otherwise—does not violate the integrity of that format.
+      While it might sound easy enough, this can be an astonishingly
+      difficult task for most of the popular binary file formats in use
+      today, and <emphasis>not</emphasis> something to be undertaken by
+      the faint of heart!</para>

      <warning>
        <para>Be aware that because the width of a keyword field is