The format proposed by the IGF is this (quoting the IGF's language):
"A 72-hole individual stroke play for both men and women, mirroring the format used in golf's major championships. In case of a tie for either first, second or third place, a three-hole playoff is recommended to determine the medal winner(s)."
Very straightforward: Men's and women's tournaments, stroke play, 72 holes each, a 3-hole playoff in the event of ties.
Now, here is how the IGF proposes selecting the field for such an Olympic golf tournament:
"The IOC has restricted the IGF to an Olympic field of 60 players for each of the men’s and women's competition. The IGF will utilise the official world golf rankings to create the Olympic golf rankings as a method of determining eligibility. The top-15 world-ranked players will be eligible for the Olympics, with a limit of four players from a given country. Beyond the top-15, players will be eligible based on the world rankings, with a maximum of two eligible players from each country that does not already have two or more players among the top-15."
The key points are that each tournament (men's and women's) will have a field of 60 golfers; and that players in the Top 15 of the men's and women's world rankings will gain automatic entry up to a maximum of four golfers per country. (That means that if one country has, say, five or seven golfers inside the Top 15, only the four highest-ranked of them make the Olympic field.)
Outside of the Top 15, players are selected based on world ranking - but only if no more than two golfers from a single country are already in the field. This stipulation is meant to diversify the field, ensuring that many different countries are represented (it's the Olympics, after all).
Assuming the IOC adopts the IGF's recommendations (and that those recommendations don't change prior to the 2016 Olympic Games), we can deduce what the Olympic fields will look like.
Let's use the men's world rankings from July 20, 2014 to give some examples. The Top 15 players at that time were:
1. Adam Scott, Australia
2. Rory McIlroy, Northern Ireland
3. Henrik Stenson, Sweden
4. Justin Rose, England
5. Sergio Garcia, Spain
6. Bubba Watson, USA
7. Matt Kuchar, USA
8. Jason Day, Australia
9. Tiger Woods, USA
10. Jim Furyk, USA
11. Jordan Spieth, USA
12. Martin Kaymer, Germany
13. Phil Mickelson, USA
14. Zach Johnson, USA
15. Dustin Johnson, USA
There are eight Americans in this Top 15, but as we've already seen a maximum of four from any one country within the Top 15 get in. So the bottom four Americans in this Top 15 - Spieth, Mickelson, and the two Johnsons - are out of luck.
Adam Scott is No. 1 in this example, and his fellow Australian Jason Day is No. 8. Those two make up the Australian contingent; since countries are limited two two golfers (unless more than two are in the Top 15), no other Australians make the field.
Henrik Stenson of Sweden is third. The next highest Swede in the rankings we are using in this example is Jonas Blixt at No. 42; Stenson and Blixt - and no others - would therefore be Sweden's contingent. So that's how the field will be filled: going down the world rankings list, adding players based on countries until a country has two golfers in the field, and until a maximum of 60 golfers is achieved.
As you can see, many highly ranked players will be passed over. And some low-ranked golfers will get into the field, because of the 2-players-per-country limit for those ranked below No. 15. This method of filling the field may result in golfers ranked in the 300s or 400s making the field, depending on how the world rankings fall.
As stated above, this is the Olympics, and organizers want to ensure a large number of countries are represented in any Olympic golf tournament. This method of filling the field may result in as many as 30 countries being represented at the Olympic golf tournament.
We can assemble imaginary fields for the men's and women's Olympic golf tournaments, using the proposed format and field - and that's exactly what I did first in October 2009, then updated at the time of the 2012 London Games, using the world rankings in effect at that time. See the sample Olympic golf tournament fields for a more in-depth look at what the Olympic golf tournaments might look like.