As with the generated load combinations, the combinations are displayed as a text string. Custom combinations can be created by typing in coefficients and load case symbols exactly as desired (for example, 1.2 D + 0.5 Rfp + 1.3 W1). The load case symbols should match those shown in the Analyzed Load Cases list. A Combination should not exceed 254 characters, including blanks. Syntax or typographical errors are reported to the user when the combinations are validated (Figure 3). A combination must not contain more than twenty five load cases.

If combinations with syntax errors exist (indicated by a red light) when the user clicks Ok, a warning will be given asking if the user wants to fix the errors. Because the combo generator does not save load combinations that contain errors, these combinations will be deleted if not fixed.