I had an uncle whose name was Russell R. Jones Hite. He named his son Russell R. Jones Hite Jr. His parents named him after a man named Russell R. Jones; I don't know if they ever knew what Mr. Jones' "R" stood for. But my uncle and cousin normally used "R." as their middle initial and usually dropped the "J" for Jones. They liked having the "R" without it standing for anything as a conversation piece.
O is a Korean surname. I once read a newspaper article about a Korean-American man living in the Washington, DC area who had all sorts of problems because his surname was O and many Americans just couldn't believe his last name was spelled with only one letter. He finally changed the spelling to "Oh" so he wouldn't have to go through all the hassles.
There have been many people (mostly men) in the southwestern US (Texas and bordering states) who have just had initials for their name. This comes from men in earlier generations using initials like "J. B." and "G. W." as their everyday names, and then having children named after them. If the infants' parents have known someone as just "J. B." their whole life, it may not seem to them that they are really naming the child after that person if they use another form besides the initials, even if they know what the initials originally stood for.