I haven't seen a breakdown of what the heck these two acronyms mean cross my dash in a while, and I've seen a growing number of people asking about them, so I've put together a short primer to get folks started. I know some folks may Google around just looking for what the acronyms stand for, while others may want varying amounts of more information and examples, so I've tried to lay it out so that you can quickly find the information you want.
Final note: these are categories that may seem to be fairly distinct, but in practice they have all kinds of odd, fuzzy edges. Please don't take my word, or anyone else's, as "gospel" truth!
First, what do those darn letters stand for?
UPG: Unverified Personal Gnosis
SPG: Shared Personal Gnosis
Second, what does all that mean?
Gnosis refers to knowing, in this case specifically knowing something internally, not necessarily because you read or saw or heard about it from an outside corporeal ("physical"/"this side of the veil") source. This doesn't preclude having "this world evidence" or supportive bits and hints in surviving sources, but it's not something where you can say "this is definitely what people historically believed or practiced" or "this is what the members of this modern faith/tradition/path believe."
Personal refers to these being things you personally know or believe, and how it only affects the personal practice of people who have that gnosis, as opposed to traditions or lore or dogma. (those and how they interact with this sort of thing and the kaleidoscope of personal practices out there are a whole other pallet of cans of worms that we'll save for another day... assuming I have that much self control!)
Unverified simply means that the gnosis is only known to be held by one person, while Shared refers to multiple people having/sharing the same gnosis. UPG often gets recategorized as SPG when two or more folks with the same UPG finally end up discussing it and realizing that they share the same UPG. SPG can be as narrow as a few people and as wide as whole communities.
If you're wondering where the line gets drawn between SPG and lore or tradition, I'll give you a peek inside one of those cans of worms I mentioned: all lore and traditions started somewhere. Especially once you get a fair number of people with the same SPG, you start to get more and more folks hearing about it first, then checking and finding that it does or doesn't work for them, which can lead to a belief spreading even more.
Heads up, I'm going to stick to little things that I hope are unlikely to spark off theological flame wars, so bear in mind that this also extends to things like the nature of the gods and spirits, afterlife beliefs, practices, "this deity is a trickster/psychopomp/fertility deity" debates, and more.
In my personal experience, Loki likes it when I give Them strawberry flavored things, Frey likes helping me brush my hair, and Gerð likes Caribbean drum music. These are not specific associations most people share, or that are found in the lore. Thus, they are things that I personally know (gnosis), and are true of my relationships with Them (personal), but are not "backed up" by other people or sources (unverified).
Lots of folks associate Loki with sweets and desserts, often without having read or heard about other folks making this association first. I know a small number of people who share gnosis that Odin is very big on (and very good at) accompanying folks to scary medical appointments. I know a few folks who associate Frigga with spiders. To the best of my knowledge, none of these are referenced in any surviving sources. These are all Shared Personal Gnosis.
Basically, these terms developed to give us a way to quickly differentiate between "this is a thing that is true for me but doesn't necessarily apply or matter to anyone else" beliefs and "this is a thing that is true for some of us that doesn't necessarily apply or matter to anyone else" beliefs and "I can dump an entire library of historical and academic sources to back this up as a belief or practice that was held by a lot of people" beliefs.
NO ONE OF THESE IS INTRINSICALLY BY "BETTER" THAN THE OTHERS.
They can all be useful in different ways and contexts. As always, "think for yourself" and "your mileage may vary/YMMV" apply to all of the above.
There's a ton of discussion and debate out there about how they can intersect and affect things, and a lot of it is absolutely fascinating, but I'm going to leave those cans of worms firmly on the pallet for now. Feel free to pull one down and open it yourself, though!
