Global/universal is this "conversations" on Amethyst?
Your NIP-05 ID is not the same as a relay but nostrplebs offers both I think.
One thing you’ll want to do is make sure you’re turning off any relays in the Global/Universe feed that you don’t want to read from. You can still write to them all, but limiting which ones you’re reading from will clean up your feed a lot.
Adding nostr:npub18ams6ewn5aj2n3wt2qawzglx9mr4nzksxhvrdc4gzrecw7n5tvjqctp424 nostr:npub18kzz4lkdtc5n729kvfunxuz287uvu9f64ywhjz43ra482t2y5sks0mx5sz nostr:npub1lqs30x7466guvx6r2cek8z9d4hpucycy7j08wx58cwx70m206q3qrscejr nostr:npub1qqqqqqyz0la2jjl752yv8h7wgs3v098mh9nztd4nr6gynaef6uqqt0n47m who know a lot more about relays work than myself.
Discussion
It’s the unfiltered everything feed, you definitely want to tame that so you aren’t seeing spam. I don’t even know what it looks like anymore since I’m using the nostr:npub1fyvwkve2gxm3h2d8fvwuvsnkell4jtj4zpae8w4w8zhn2g89t96s0tsfuk filtered relay.
Yes, I believe different clients have different names for the global feed but they're more or less the same feed.