my %Fields = (
'filename' =>{

Type => 'A'{
Name => 'Abstract'{
};
};
....

##</code><code>##

%F = ( aa => {
               BB => 'cc'
             },
       ll => {
               NN => 'xx',
               MM => 'yy',

      )

##</code><code>##

perldoc perldsc