minor edit

diff --git a/doc/readme.html b/doc/readme.html
index 7f3bb705ce9e993b8d2c220e444f149a156a94fc..83d0e610f9f8049a291a7a2d9c25ac2eda80dc35 100644 (file)
--- a/doc/readme.html
+++ b/doc/readme.html
@@ -289,11 +289,13 @@
          name and line number of where the problem occurred.
        </p>
        <p>
-         Debug mode, by default, uses the <code>-Og</code> flag. It promises most of the
+         With GCC Debug mode, by default, uses the <code>-Og</code> flag. It promises most of the
          debugging experience of <code>-O0</code> but at a better performance.
          This is a reasonable choice for unit tests and enables numerous asserts
          within the library. Sometimes, however, one needs Debug mode to use
-         <code>-O0</code> (e.g. GCC 6.2.0 optimizes out local variables with <code>-Og</code>).
+         <code>-O0</code>, where all compiler optimizations are avoided and code and variables
+         are exactly as indicated in the C++ program (e.g. with <code>-Og</code> GCC 6.2.0
+         optimizes out local variables).
          This can be achieved by configuring <acronym>deal.II</acronym> with
          <code>-DDEAL_II_HAVE_FLAG_Og=false</code>.
        </p>