 to
the normal regular expression syntax accepted by the Tcl <B><A HREF="../TclCmd/regexp.html">regexp</A></B> and
<B><A HREF="../TclCmd/regsub.html">regsub</A></B> commands.
<P><DT><A NAME="M7"><B>TCL_REG_EXTENDED</B></A><DD>
Compile extended regular expressions
(&#8220;ERE&#8221;s).
This mode corresponds
to the regular expression syntax recognized by Tcl 8.0 and earlier
versions.
<P><DT><A NAME="M8"><B>TCL_REG_BASIC</B></A><DD>
Compile basic regular expressions
(&#8220;BRE&#8221;s).
This mode corresponds
