Frequency: The word is one of the 3000 most common words in English.
Note: 'Yours' is the second person possessive pronoun. 'Yours' can refer to one or more people.
1.
A speaker or writer uses ~ to refer to something that belongs or relates to the person or people that they are talking or writing to.
I’ll take my coat upstairs. Shall I take ~, Roberta?...
I believe Paul was a friend of ~...
If ~ is a high-stress job, it is important that you learn how to cope.
PRON
2.
People write ~, ~ sincerely, or ~ faithfully at the end of a letter before they sign their name.
With best regards, Yours, George...
Yours faithfully, Michael Moore, London Business School...
~ truly: see truly
CONVENTION