After having seen the code VIVID5 for a bunch of Dell products, I decided to try out a few variants and found that VIVID20 is a valid code too. A quick DuckDuckGo search took me to a page called Dell Youniverse that's part of Vivid Sydney.
It reads at the bottom:
"To celebrate Dell being at Vivid Sydney, we are offering you a 20% discount on any Dell XPS (excluding clearance models). Offer not in conjunction with any other offers. Apply Coupon “Vivid20” at checkout. Offer valid between 27 May – 30 June 2022."
I've tried it with a few XPS laptops and it does not seem to stack with existing discounts, so it's only useful for anything having a discount of less than 20% already.
Update: I just noticed it works for XPS Desktops as well. And snep mentioned below that the code stacks with the 7% student coupon. Thanks!
Note: VIVID20 may stack with VIVID5 - credit r0xz