Ipposnif variables contain information about the markets, the runners, the trades and more. They can be used in SQL expressions and SQL assertions of the strategies.
Some of these variables can be used directly.
For example @capital contains the current capital of the strategy (initial_capital+profit), can be use to specify the size of the bet:
Other variables (for ex. @id_race, @id_horse and @id_strategy) are tipically used as parameters passed to functions.

If the variable you need is missing, read in the Customize page how to add a new one.