>>8880887 (lb)
>>8880629 (lb)
Not a misspelling.
President John F Kennedy was often referred to as 'Jack' during his lifetime, esp by people who knew him. It is an easy thing to find, even in Wikipedia:
"John Fitzgerald Kennedy (May 29, 1917 – November 22, 1963), often referred to by his initials JFK and Jack, was an American politician who served as the 35th president of the United States from January 1961 until his assassination in November 1963. "
https://en.wikipedia.org/wiki/John_F._Kennedy
He and his wife were also referred to as 'Jack and Jackie' as seen in this book title.
Also Pic of John Kerry and John F Kennedy on a sail boat.