SACS can design a rectangular hollow section (RHS) joint by using the RHSOPT line.
At this moment, we have only implemented the CIDECT Design Guide 3, which is available in columns 8-11 of the RHSOPT line.

If you are looking for the other joint check option of CIDECT, which is not available in SACS, you may put an enhancement request in our IDEAS portal so other users can also vote for it.