Improved description of "what's this" for placeholder in Find and

Replace dialog. This relates to bug 2558.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>

tdeutils/kfinddialog.cpp

@@ -254,10 +254,13 @@ void KFindDialog::init(bool forReplace, const TQStringList &findStrings, bool ha
     TQWhatsThis::add ( m_replace, i18n(
             "Enter a replacement string, or select a previous one from the list.") );
     TQWhatsThis::add( m_backRef, i18n(
-            "<qt>If enabled, any occurrence of <code><b>\\N</b></code>, where "
-            "<code><b>N</b></code> is a integer number, will be replaced with "
+            "<qt>When regular expressions are enabled, you can select part of the searched text by "
+            "enclosing it within parenthesis. Placeholders allow you to insert such text in the "
+            "replacement string, similar to how backreferences are used in sed. When enabled, "
+            "any occurrence of <code><b>\\N</b></code> (where <code><b>N</b></code> "
+            "is a integer number, e.g. \\1, \\2, ...), will be replaced with "
             "the corresponding capture (\"parenthesized substring\") from the "
-            "pattern.<p>To include (a literal <code><b>\\N</b></code> in your "
+            "pattern.<p>To include a literal <code><b>\\N</b></code> in your "
             "replacement, put an extra backslash in front of it, like "
             "<code><b>\\\\N</b></code>.</qt>") );
     TQWhatsThis::add ( m_backRefItem, i18n(