STEP AP242 Support

How much of AP242 is supported? Per https://www.opencascade.com/doc/occt-7.4.0/overview/html/occt_user_guides__step.html, it says that AP242 is not fully supported by OCCT:

• "some parts of AP242 are also supported"
• For exporting STEP files, it mentions "AP242DIS: AP242, DIS version."

Is it just that the AP242 DIS (draft international standard; http://www.ap242.org/ap242-standard) is supported for both importing and exporting?