Infernal/Demon Lore

This is the sum of a character's knowledge about the infernal. Almost by definition, it has a subtly Judeo-Christian slant to it, dealing the contrast between the sacred and satanic, the struggle for souls, and the true nature of the World of Darkness. Infernal Lore and Demon Lore are the same thing.

Infernal Lore 1 - What you learned from your Ouiji board

You believe that demons are real, and that they possess infernal powers of some sort.
You can tell completely fake demon/infernal texts from those that hold at least a kernel of truth.
You believe that demons are out to make pacts for people's souls.
You are certain that it's possible for those who are not demons to get access to infernal powers.
You think that demons and infernal powers can probably be countered by faith of some sort.
You can probably find the closest satanic cult, and become one of their trusted members or even mentors by demonstrating your knowledge.
You have heard of a group of demon worshippers called the Salubri; the sign of vampiric infernalism is a third eye in the middle of the forehead.

Infernal Lore 2 - What a would-be demonologist would know

There are several kinds of demons, and they may not all serve the same masters, or even pursue the same interests.
There is no single 'satan-like' figure, no Lord of Hell, no leader of the infernal hordes.
There are ways of summoning demons, and of engaging in pacts with them. You may possess tomes discussing those methods, although none of them go into sufficient detail.
Deals with demonic figures rarely work out as planned. You've heard of rumors that demons control those who summoned them like puppets, or even use them for more insidious purposes.
You may have briefly encountered the infernal yourself, either in the form of a demon, or some of its servants.
You are aware that there are supernaturals that are demonically tainted, but you know no details about them.
You have heard that the three-eyed infernalists - the Salubri - were ordered hunted down and killed by the (vampires known as the) Tremere.

Infernal Lore 3 - What a studied occultist would know

You are aware that there are certain powers that supernaturals can use that are demonically tainted. If you're a vampire, you may have heard about Dark Thaumaturgy. At ST discretion, you may recognize the effects of the more blatant Dark Thaumaturgy rituals in action.
You know that infernal powers do not come without a price, and that using such powers means that the relevant character is tainted by the infernal, and obeys only one master.
You probably possess several volumes dealing with the nature of the infernal, what it does, and how to fight it.
You may even have some books that deal with details about summoning demons, but something seems to be lacking.
You know about this history of the Inquisition in the Dark Ages, and how they related to the vampiric Anarch Revolt; you also know about the modern Inquisition, in the form of the cabal of infernalist hunters within the Sabbat.
You know that there are demons who walk the earth, and demons who are bound to the earth. Those who are free may look like anyone, and their powers are poorly-understood.

Infernal Lore 4 - What an Arcanum Scholar would be killed for knowing

You possess sufficient knowledge about the infernal to perform a full and proper ritual for summoning infernal forces. You are aware of some of the common names of demons, which is sufficient to summon them. Get in touch with your Head ST for doing so. (WARNING: Summoning demons will almost certainly lead to your character's horrific death, whether immediately or after a prolonged servitude to the infernal. YOU HAVE BEEN WARNED.)
You are aware that there are a number of demons who were released upon the world fairly recently. They can take any form, although you are familiar with their demonic form as described in Demon: the Fallen. (wings, spikes, etc)
Not all demons are the same - there are differences in outlook and purpose, and some of them don't seem to be inherently interested in causing harm, and their goals are unclear.
You can recognize almost all infernal Thaumaturgy Paths and Rituals.
You are familiar with the Discipline of Daimoinon, and know basic details about the Baali. (roughly what Baali Lore 2 would give you)
You know that the Third Eye on some vampires has no background whatsoever in infernalism, and that the Salubri are not inherently infernal at all.
You know about the Nephandi, and have an approximate idea of their nature and goals.

Infernal Lore 5 - The Edge of the Abyss

You know the names of all major demons, and may even be familiar with one or two of their principal pawns. (Check with your ST)
You believe you understand the purposes of some of the more advanced Baali rituals, and are intimately familiar with the purpose of Call the Great Beast and its history.
You know about the true nature of the Shadowlands and the Abyss, as described in Demon: the Fallen, and you may even have an idea about the true nature of Koldunism.
You have an inkling that the true origins of the vampiric Disciplines of Vicissitude and Obtenebration may be infernal in nature, although there is no infernal taint on their users, per se.
You are aware that the mythical figure of Lucifer is an actual demon, although details of that are elusive.
You may know the full extent of some of the powers of the Fallen, as described in Demon: the Fallen. (ST discretion)
You know for a fact that entering into a pact with a demon will lead to your damnation. You are aware that summoning an Angel - if you have an appropriate name - is unlikely to summon an actual Angel, and will very likely be a type of umbral spirit instead.
You are aware of the concept of 'Celestial' names, and realize that without a Celestial name, you can never bind a true Demon or Angel. Unless acquired in-game somehow, you don't know any Celestial names.

Sources:
Thanks to Liz and Jack of Emerald City Reborn