Exillic Noldorin and Quenya - What's the difference on the dictionary?

I am trying to write a story set within Middle-Earth, and my character's roots go back to Gondolin and the Noldor. I want to ensure I am using the correct language (kinda to avoid being flame-grilled by intense fans and kinda for my own enjoyment) so here's my question:

If Exillic Noldorin is just Quenya (as my Tolkien Gateway research has revealed) why is there an entirely separate section for Noldorin on this dictionary? Is there a difference I missed? I'm not sure which one to use for names and such, I already did quite a bit before stumbling across this and I'm afraid to change anything before being 100% certain about it XD

Please help a confused writer, it would be most appreciated!

That’s an artefact of Tolkien changing his mind over the years:

1. In the late period of his life (1950s onwards, the conceptual period we can see in the Lord of the Rings), the Noldor used Quenya and the Welsh-like language is called Sindarin.
2. Before that, the Welsh-like language was called Noldorin (or earlier Goldogrin) and was spoken by the Noldor, the Ilkorindi spoke Ilkorin/Doriathrin.

This lexicon contains words from all conceptual periods. When something is labelled as Noldorin, it means that it’s meant in the second sense. To illustrate this with an example: Let’s say you want two characters to say ‘book’ and ‘arm’:

• For a Ñoldo, you’d choose Quenya. That should be rather easy for those words: parma, ranco,.
• For a Sinda the question becomes more complicated: There is no word for ‘book’ in the Sindarin corpus, but we know one for the Noldorin from the 1930s: parf. Since we see many words carrying over from Noldorin to Sindarin and there is no (obvious) argument against it, we can just use parf as if it were Sindarin. For ‘arm’ the same problem occurs: No known Sindarin word, but Noldorin rhanc. However just using rhanc in Sindarin wouldn’t do: we know that Tolkien changed a couple of phonetic development rules, and among those, it appears that he deleted the change r- > rh-, so I would use ranc instead. For ‘finger’.

This process of deciding which words to use can get rather involved and there is no fast way to explain the rationales behind this. And this problem exists for Quenya as well (I just choose words that illustrate this for Sindarin/Noldorin)

Also, just to mention it: name formation is a quite involved process, feel free to request input on your ideas here.

Apologies for my late response.

Thank you so much for this answer! It's very helpful, and clarifies my thoughts. Now I can be certain about what I'm doing, haha.

I'm aware of the naming traditions of the Elves, including the slight differences between the races, but if I am unsure I will definitely consult here! Though I am not too pressed, as it is simply a fanfiction and I know I will never be utterly correct, lol.

I adore this site, a blessing from Eru himself <3