their structure.</P>

<P>Ignorable aspects of the scanning process are defined in Cocol by</P>

<PRE>   Comments  = &quot;COMMENTS&quot; &quot;FROM&quot; TokenExpr &quot;TO&quot; TokenExpr [ &quot;NESTED&quot; ] .
   Ignorable = &quot;IGNORE&quot; ( &quot;CASE&quot; | CharacterSet ) .
</PRE>

<P>where the optional keyword NESTED should have an obvious meaning.  A
practical restriction is that comment brackets must not be longer than 2
characters.  It is possible to declare several kinds of comments within a