display tag : the media attribute

media :
 Use this attribute to keep a caption from being output during an export. The caption will only render for the named media type(s) - it won't be added to the table if the current request media is not supported. Can be any space separated combination of :

'html',
'csv',
'xml',
'all',
'excel'.

the Default is  'all'. 

<display:table  export="true">

<display:column media="html" >
...........
</display:column >

</display:table >