The 1988 Olympic eligibility does really deserve the gold medal for intricacy....
I have the official circulars released by FIFA at that time. This is a summary of what they state:
The Olympic Football Tournament - Seoul
1988, Preliminary and Final Competition - is open to all players except
players from Europe and South America who have participated in matches
of the FIFA World Cup, Preliminary and/or Final Competition.
European and South American players who have played less than 90
minutes in one single match of the Preliminary and/or Final competition
of the FIFA World Cup, are eligible to participate in the Olympic
order to clear up any misunderstandings, we would like to specify - in
agreement with the International Olympic Committee - that "participated" means having played at least one
full match of said competitions.
So, just to cite a couple of concrete examples: Rui Águas
of Portugal played 36 minutes
against England at the 1986 World Cup and was therefore eligible for
Portugal Olympic (and in fact he faced Italy Olympic in the 1988
Dragan Stojković and Davor Jozić of Yugoslavia competed at Seoul 1988,
even if they had previously played some minutes over a qualifying game valid for the
1986 World Cup.
On the contrary, all
the European and South American players who had previously appeared for 90 minutes or just
for some fragments in more than one World Cup game, were excluded. For
this reason, Per Frimann of
Denmark, who had previously appeared in three World Cup qualifying
games, was disqualified because ineligible for the Danish Olympic team.
the last time in the history of the Olympic Games, some "A" National
teams competed in the event (Zambia and Australia, just to mention two).
Difficult to understand why the United States didn't regard their
matches at Seoul '88 in their official list, as they were not affected
by restrictions and could send their strongest team.