The elements within each strategy definition represent all the available inputs to the general-purpose backtesting engine of RealTest. A few of them are required, the rest are optional (with obvious defaults).
To see a quick list of supported elements, press F2 with the cursor in a blank space within a strategy definition (but not at the start of a line):
(Several others have been added since this screen shot was taken -- the list now has a scrollbar.)
Another way to think of these strategy elements is to imagine that rather than using scripts, RealTest had a strategy definition dialog box.
Some of the elements below require a constant, such as "Long" vs. "Short", or "ThisClose" vs. "NextOpen".
Other elements require a formula that evaluates to true (1) or false (0), and others take a formula that evaluates to a number.
See Strategy Element Value Types and Defaults for a table of element types.
The following are more detailed descriptions of each strategy element.