Maecey, a director of corporate communications, wrote to me with a question. She wanted to know when the comma rule for direct address had become proper usage. She was referring to the commas in these sentences, which address the reader directly:
Brandy, will you attend the writing class in Seattle?
No, Karthik, I attended the class last week in Portland.
That comma has been standard for the many years I have been studying business writing. But I wanted to give Maecey a better reference point than my years of study. So I checked my recently acquired copy of Handbook of Business English, by George Burton Hotchkiss and Edward Jones Kilduff, both of New York University.
The book was published in 1914. It includes the comma for direct address in this example:
You will understand, Mr. Fall, that we have done our best in this matter.
The rule Hotchkiss and Kilduff provided with the sentence does not refer to direct address. Instead they wrote, "To set off a noun used in apposition with, or in explanation of, another noun or pronoun, use commas." Applying that rule to direct address, whenever you are writing to you (the reader) and use his or her name, the name is a noun in apposition and should be set off by commas.
I hope Maecey's coworker is convinced that the use of commas in direct address has been around for a while.