It's a modification of what we'd call full suspension but you probably recognize as just general hanging, i.e. kicking a chair out and completely suspending yourself mid-air. The idea behind partial suspension is to try to make the experience far less painful by only suspending the upper half of your body and having you fall into the knot after losing consciousness, the loss being attained from replicating a blood choke.
Video showing a blood choke ^^
Process works by constricting the carotid arteries and cutting off the brains access to blood, while trying to avoid constricting your jugular veins and creating the immense head pressure/exploding feeling that would otherwise be associated with suffocation/hanging. You'll pass out much faster with your carotids constricted, and the idea is that if you pass out from carotid compression, you'll fall into partial suspension and suffocate while unconscious, averting the worst of the experience.
Are you new to hanging? Or maybe just trying to find out if hanging is the right method for you? This reading guide has you covered! This is your one stop shop to both partial suspension hanging and full suspension hanging. This is a reading guide to the guides I published on this forum so far...
sanctioned-suicide.net
I haven't been able to get it to work for me, but for some it's very effective. One of the main benefits is the ability to do it basically anywhere with anything that can tie and hold a knot. This reached a level of ludicrousness for me as I once was practicing positions against my doorknob and my dad came over to visit and knocked on the door while I was on the other side trying to hang myself and had to quickly pull the robe tie I was using off the door before he came in and realized what I was doing. Because of your means, this method might be ideal.
Edit: I would personally echo OP's advice in the linked threads to go for full suspension as even if you fuck it up and it hurts, it's the #1 suicide method of American teenagers everywhere and if those kids could figure it out back then it will work so long as you have patience (to tie a good knot) + time (to not be found). Sometimes though the frustration of partial suspension failures is needed to encourage one to go for full suspension.