UPDATE, 10:33a: American Papist has posted a close-up of the shield:
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Per CNSNews.com, April 28:

President Barack Obama is expected to wear the traditional doctoral robe featuring the cross and prayer of the Virgin Mary when he speaks at… Notre Dame next month, White House Press Secretary Robert Gibbs told CNSNews.com White House Correspondent Fred Lucas on Monday….


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“I honestly don’t know what the dress code is for that day. I can assume that the president would wear what one traditionally wears at that commencement,” Gibbs told Lucas during Monday’s White House press briefing.
Notre Dame spokesman Dennis Brown told CNSNews.com earlier this month that the university expects Obama to wear the robe.
The question was posed after the monogram “IHS,” which symbolizes the name of Jesus, was covered up when Obama spoke at Georgetown University, a Jesuit university. Georgetown officials said the “IHS” was covered at the request of the White House.

Photo left, courtesy of the White House, is of Laura Bush speaking at Georgetown in 2006 with “IHS” visible; center photo is close-up of “IHS”; photo right shows “IHS” covered for Obama’s recent speech. Click to enlarge…
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