The Ars Technica article Rocket Report: A new Delta 2, Blue Origin inks with NASA, a fiery Falcon Heavy says:
Boeing seeks to ship SLS core stage by the end of 2019. With a renewed emphasis from the Trump administration on completing the large Space Launch System rocket for a 2020 flight, NASA and prime contractor Boeing have reworked the final assembly plan for the first SLS Core Stage to bring its scheduled completion date back to the end of 2019, NASASpaceFlight.com reports.
Skipping the Green Run test likely ... We hear that NASA Administrator Jim Bridenstine will be briefed at the end of this week on this plan to accelerate development, which likely will recommend skipping a "Green Run" test of the full core stage at Mississippi's Stennis Space Center. There are risks to this, both political (from Mississippi's delegation) as well as technical due to the problems such an all-up test firing may uncover. Still, if NASA has any chance to launch the SLS rocket in 2020, it must make difficult decisions and trade risk.
I found the NASA Spaceflight article NASA Stennis wrapping up B-2 Stand activation for SLS Green Run testing which talks about a Green Run project, but most of the article is about resting a deluge system rather than a static launch test.
Question: What exactly will/would be the "Green Run test" for SLS?