I just had „iirc“ in the card of Anna Cupa (his wife?), with 3 other (probably) family members next to him in the passenger list. All five entries in the „sponsor“ column read „IRC“, so maybe iirc is a typo?
(I can’t post anything for Anna`s card, but @Helle74 has got it here.)
[edit]
After their return to Munich they seemed to have sailed to the US on Aug 07, 1951 („General Sturgis“), again the entries read „IRC“ (see passenger list)