The Few, the Proud, the Elf-Friends!

[Inziladun]

Throughout the books we have references to so-and-so being an 'Elf-friend'. These appear to be those of alien race (to Elves) that, for some reason, an Elf takes a fancy to and bestows some sort of honour.

Gildor does it to Frodo:

'I name you Elf-friend; and may the stars shine upon the end of your road!'.

FOTR Three Is Company

And later, Goldberry is apparently able to divine that Frodo has that status:

'But I see you are an elf-friend; the light in your eyes and the ring in your voice tells it.'

In the House of Tom Bombadil

So being designated an elf-friend leaves physical and auditory traits? Does an elf 'bless' someone and change them spiritually? I say 'bless', but being an elf-friend is obviously different from the 'blessing' Elrond gives to Frodo in Rivendell after the Ring is destroyed.

Elrond named Húrin, Túrin, Hador, and Beren as elf-friends. The tendancy would be to think of it as just an honourary title, but Frodo exibited perceptible evidence of his status. And if it didn't cause any actual change in the person being 'named', how were the other elves to know it had been done?

So the questions are, what was the real purpose of saying someone was an elf-friend, and did it have any real effect on the person's physical or spiritual makeup?