The SoftLayer API is built around the same system of user permissions that power the SoftLayer customer portal. What the API exposes and allows depends on the user account that is making the call and that user's permission set.
Many of the methods in the SoftLayer API return arrays of data types. In these cases it may be useful to limit the number of results that the API retrieves from your method call. Fortunately SoftLayer provides an easy way to accomplish this via a method analogous to the SQL <tt>LIMIT</tt> statement that you can apply in the header of your method calls. Result limits are optional for all method calls, and a method's manual page states whether or not it can use a result limit. Methods that retrieve only one item cannot use result limits.