[Maédhros]

If we opt to merge notations, we might follow what has I think become the common practice in the last few parts of the FoG revisions, and use [ ] for both normalization and grammatical insertions.

As a matter of fact, the / / for outline expansion has also been replaced in common usage with [ ]. I'm not sure now whether we should go back to / / or simply use [ ] for normalization, grammatical insertions, and outline expansion.

I would rather keep it simple and use the [] for normalization, grammatical insertions and outline expansions.
Aiwendil, what is the difference between grammatical insertions and outline expansion?
To me this seems:

/ / Material altered in accordance with our principle 6c; mostly used for expansion of outlines. In this case, I will show the deletion of the original as well; for example: {Coming thither of Elwing} = /Elwing came thither/.

like a grammatical insertion, which changed the order of the sentence.

One possible convention would be to indicate what base text one is using at the beginning of a section, and then only indicate changes (that is, not copy the whole text) using the angular brackets as necessary to indicate insertions from other sources. Then, if the base text changes for a significant length of text, indicate the switch.

Agree 100% with that. That really happened a lot with the Ruin of Doriath section.

One final thought is that it might be worthwhile to generate a complete standard list of abbreviations. Some are obvious and others have been more or less fixed by convention - e.g. LQ is the Later Quenta Silmarillion, TO is the outline found in the final note on "Tuor" in Unfinished Tales, etc. But there may be cases where no obvious and immediately recognizable convention is apparent.

Yes, we should definitely do that. What I had in mind is:

BoLT 1 The Book of Lost Tales 1 (HoME 1).
FG "The Fall of Gondolin" from The Book of Lost Tales 2 (HoME 2).
TE "The Tale of Eärendel" from The Book of Lost Tales 2 (HoME 2).
Q30 "The Quenta", written in 1930, from The Shaping of Middle-earth (HoME 4). Quotations are from §16 and from §17 in the Q2 version including later emendations as per the notes.
AB 2 "The Later Annals of Beleriand", written about 1936?, from The Lost Road (HoME 5). Unknown to Christopher Tolkien when he produced QS77.
TO "Of Tuor and his Coming to Gondolin", written about 1951 from Unfinished Tales
Elessar The Elessar from "The History of Galadriel and Celeborn" in UT.
TY "The Tale of Years", (1951-52), from The War of the Jewels (HoME 11)
PG The Parentage of Gil-galad, a long note by Christopher Tolkien appended to SF, containing material by his father on this matter.
SF "The Shibboleth of Fëanor", Feburary 1968 or later, in the chapter of the same name from "The Peoples of Middle-earth" (HoME 12).
QS77 Quenta Silmarillion as published in The Silmarillion edited by Christopher Tolkien in 1977.
QE "Quendi and Eldar" from "The War of the Jewels" (HoME 11)
NA "Narn I Chîn Húrin", from "Unfinished Tales".
ET "The Etymologies", from "The Lost Road and Other Writtings". (HoME 5).
QS "Quenta Silmarillion", from "The Lost Road and Other Writtings". (HoME 5).
WH "Wanderings of Húrin", from "The War of the Jewels" (HoME 11).
TN "Tale of the Nauglafring", from "The Book of Lost Tales II" (HoME 2).

There are lots that are missing, but I think that we can work with that for the time being.