I haven't played much with formats, but judging from perlref if anything would work it would be: 
*foo{IO}

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In reply to Re (tilly) 1: Format references by tilly
in thread Format references by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


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