For angle sections, you can specify single or double angle sections.
Choices are: 
Single angle, 

Double angle with short legs connected, 

Double angle with long legs connected, 

Double angle starred (equal angles only). 
The diagrams above show the orientation of a single angle section and the available double angle sections. Note that the zaxis is the major axis in all cases.
For double equal angles, the long leg is assumed to be the vertical leg in the diagrams above. Note that in SPACE GASS 10 and earlier, double equal angle sections with long legs connected were adjusted internally and treated as though their short legs were connected. This adjustment was removed in SPACE GASS 11 and later versions.