4 Of the coming of the Elves

[Findegil]

Okay, I did the work with the Notes directly, so why not share it:

... Some of these finally entered Beleriand, CE-EX-72{not} long before the return of {Morgoth}[Melkor]. These were under the leadership of Denethor, son of Denweg [footnote: Lenwe is the form in which his name was remembered in Noldorin histories. His name was probably *Denwego, Nandorin Denweg. His son was the Nandorin chieftain Denethor. These names probably meant 'lithe-and-active' and 'lithe-and-lank', from *dene- 'thin and strong, pliant, lithe', and *thara- 'tall (or long) and slender'.], who became an ally of Elwë in the first battles with the creatures of {Morgoth}[Melkor]. ...

CE-EX-76 <Q&E Sindar{
Less commonly the form Sindel, pl. Sindeldi, is also met in Exilic Quenya. This} was the name given by the Exiled Ñoldor [footnot: Lake Mithrim, meaning originally 'Lake of the Mithrim'. Mithrim was a name given to them by the southern-dwellers, because of the cooler climate and greyer skies, and the mists of the North. It was probably because the Noldor first came into contact with this northerly branch that they gave in Quenya the name Sindar or Sindeldi 'Grey-elves' to all the Telerin inhabitants of the Westlands who spoke the Sindarin language.
Though this name was also later held to refer to Elwe's name Thingol (Sindikollo) 'Grey-cloak', since he was acknowledged as high-king of all the land and its peoples. It is said also that the folk of the North were clad much in grey, especially after the return of {Morgoth}[Melkor] when secrecy became needed; and the Mithrim had an art of weaving a grey cloth that made its wearers almost invisible in shadowy places or in a stony land.
This art was later used even in the southern lands as the dangers of the War increased.] to the second largest of the divisions of the Eldar. [footnote: See above{, p. 381}<the 1st paragraph of this sub-chapter>. The proportion, per 144, of the Eldar remaining in Middle-earth was reckoned at 26, of which about 8 were Nandor.] It was applied to all the Elves of Telerin origin that the Ñoldor found in Beleriand, though it later excluded the Nandor, except those who were the direct subjects of Elwë, or had become merged with his people. The name meant 'the Grey', or 'the Grey-elves', and was derived from *THIN, PQ *thindi 'grey, pale or silvery grey', Q þinde, Ñ dialect sinde. [footnote: On the origin of this name see {Note 11}<referenc tothe footnote above>]
The Loremasters also supposed that reference was made to the hair of the Sindar. ...

Respectfully
Findegil