While people are quite, and even singularly, focused on things that appear in The Lord of the Rings: Rings of Power that aren't in Tolkien's writings anywhere, what I find interesting are things that the show is using or showing from what Tolkien wrote, but are outside the books we know 100% that Amazon bought the rights to: Lord of the Rings, including Appendices, and The Hobbit. Famously, as soon as the last promotional map landed, we saw the map of Númenor with named locations, which only appears in Unfinished Tales. But there are have been other little things, like names, that have been used, and seems to support the reported situation that the showrunners can ask the Estate for permission on a case-by-case basis to use elements from other writings.
If this seems rather minimal, then rest assured it is no joke. Peter Jackson and co had Gandalf mention the other two wizards, aside from Saruman and Radagast, but 'conveniently' forget their names (which are published outside LotR/Hobbit). The specific name Annatar isn't in LotR/Hobbit, and so this name couldn't be used in a licensed Middle-earth-based game that included the character, leading to a made-up name being used instead.
Now that season 1 has finished, can we compile a list of things/events/places/names/etc that appeared in it that are verifiably from a non-LotR/Hobbit Tolkien book? Here by 'LotR' I include the appendices, and don't just mean the narrative of the War of the Ring.
