The first Olympic appearance of football was in Paris 1900, although it was merely a demonstration sport (an additional entertainment to the main event of the World Fair) and no medals were awarded. In fact, it was not a real tournament at all, since it was played by clubs instead of national squads representing countries. It wasn't until London 1908 when football acquired official status as Olympic sport, and for the first time an international tournament (with national squads) was contested.
During the first editions of the Olympic Football Tournament, only amateur players were eligible (according to the Olympic spirit), and this made it difficult for the traditional powers to send their best squads to the Games. After the inception of the World Cup in 1930, professionalism spread throughout the world of football, and the gap between the World Championship and the Olympic Tournament widened. At this juncture, the main beneficiaries were the Eastern Bloc countries, where the top athletes were sponsored by the State while retaining their status as amateurs. No wonder then that, between 1948 and 1980, the Communist teams dominated the Olympic Tournament, winning 23 out of 27 medals.
To re-capture the general interest for Olympic football, the IOC decided to admit professional players in the 1984 Games of Los Angeles (on condition that they didn't participate in a World Cup before, in order to avoid a conflict between these two competitions). Many European and American countries then fielded very young teams in the Olympiads, and this resulted in a new regulation agreed upon by the IOC and FIFA in order to achieve parity: Olympic players must be under 23 years of age, with three over-23 players allowed per squad. The new regulation was introduced at the 1992 Games, and since then the Olympic Football Tournament has become the unofficial "Under-23 World Cup."
• Official FIFA scores and statistics extended and corrected with multilingual edition. All the names of players, referees, stadiums, and cities are written in their original spelling (or a standard transcription into Latin characters, in the case of other alphabets). This is the reason why some names may slightly differ in form with respect to other unstandardized information sources.
MAIN REFERENCE SOURCES
• FIFA Olympic Football Tournament / FIFA Technical Reports. I use them as the main statistical source for line-ups, scorers, scoring time and substitution time. Whenever there is a small discrepancy between it and other sources (especially for timings, let's say 1-2 minutes difference), I stick to FIFA; otherwise, I always use the most trustworthy of all the sources I check (especially the official Olympic reports).
• Official Olympic Reports.
• RSSSF Olympic Tournament.
• Sports Reference. A complete reference for football players' names.
• Different other online sources for local information on particular teams (mostly Argentina, Brazil, China, Denmark, India, Iraq, Japan, South Korea, Mexico, Poland, Spain, Turkey, Uruguay and USA).
• Special acknowledgment to Eduardo Mendoza for his corrections and historical research on the Olympic Tournament.