Hey, I opened up the docs that are linked on the video and they say that they're legacy, does this still work in unity 2018?
Sometimes they update the docs to the latest version of Unity, but everything is still essentially the same. I'm not sure what they changed in the docs as the updated link looks almost identical: https://docs.unity3d.com/Manual/SL-Properties.html At the very top you can switch back to different versions of Unity docs to see what was changed, although it just goes back to the main docs home page.
Oh, that's weird, I thought it was outdated because when I clicked to switch to the 2018 version it sent me to the front page of the doc, thanks for answering!