When Ahn Yoon-joon, 86, meets his two younger sisters this week that he has not heard from in more than 60 years, there is much they won't be able to talk about.

A guide book distributed to the elderly South Koreans chosen by lottery to meet family members separated by the 1950-53 Korean War includes a long list of do's and don'ts — but mostly don'ts.

"You can't ask everything you want to ask. This is not a reunion, but just a meeting that's staged," said a frustrated Ahn, who missed out in lotteries for past reunions and said the restrictions have dampened his enthusiasm for the upcoming trip.