It is pretty comprehensive.
Click in and you will see the name of the BTO, flat types, number of units on offer, balance units left and ethnic quota.
Obviously the number of units available for selection is important. But what is most important is the ethnic quota. And by that, I do not mean the ethnic quota overall for the flat/room types.
Each block has a fixed ethnic quota. If you happen to be say Chinese, and there are zero ethnic quota left for Chinese in a particular block which you are interested in, you can go fly a kite.
That is even if there are many units left in that block unselected. You are still not gonna get your foot in any door.
So, pick a few choice units from various blocks in the BTO. At least you can go down the list when your choice block is filled.
It's also a pity that the 3-rooms at Canberra BTO are limited by income ceiling of 5k. Otherwise, it would have been a 'good buy' given its proximity to the MRT station and being a mixed commercial/residential.