Dimensioning of General sections for the design by using EN 1993-1-1:2005 code

While creating a General section, how do we know what is the meaning of D, B, TD and TB values for each section type selected by the GST parameter in the EN 1993-1-1:2005?

 
Eurocode 3 (EN 1993-1-1:2005) is the only design code in the STAAD.Pro as of now, which can design General section not only as an I section, but also as some other standard section. The table below summarizes the meaning of D, B, TD and TB values in the General section dialog for each standard section, when it is designed by using EN 1993-1-1:2005 and assigned with some specific GST parameter's value.