Create a custom section by drawing a section profile using line and arc drawing elements.

1. Draw section profiles using drawing elements such as lines, multiple segment lines, arcs, or shapes.
   

   fig. 1, Multiple segment line (left), Lines and Arcs (middle), Shapes (right)

2. In the Structural ribbon, select (Create Custom Section). Opens the Custom Section Editor. The Status bar prompts you with "Custom Section > Identify element".
3. Enter a unique name in the Name field.
4. Turn on the Use Thickness option and enter a value for Thickness.

   Leave Use Thickness off.

   Note: The lines and arcs form a closed profile (fig. 1, middle). Use Thickness is optional. If on, a hollow section is created. If off, a solid section is created.
   Restriction: If a closed profile is constructed by joining individual lines and arcs (complex chain), the tool does not recognize it as a valid closed profile, and displays the "Thickness Not Specified" warning dialog. You can make a valid closed profile with lines and arcs using the Place SmartLine tool (places multiple segment lines, see MicroStation Help for more information.).
   Prompt: "Custom Section > Identify element"
5. Select one of the profile elements. Prompt: "Custom Section > Identify next element or reset to add opening".
6. Repeat for the other arcs and lines that comprise the profile. Do not reset until all are selected. The prompt "Custom Section > Identify next element or reset to add opening" is repeated.
7. Reset (right mouse click).

   Reset twice if you left Use Thickness off (and you have a valid closed profile).

   Note: Opting for this option does not use multiple selections (step 6).

   The new custom section is created. It is added to the Preview and the Available Sections in the Custom category.