Is a resignation a request for FMLA  leave? Of course not most would say, but it  depends on whether you ascribe to words their plain meanings.  One of the more well-known  exchanges concerning the meaning of words occurred between Humpty Dumpty and Alice in "Through the Looking Glass."

“When I use a word...‘it means just what I choose it to mean — neither more nor less," Humpty said. "The question is"’ said Alice,"‘whether you can make words mean so many different things."

The Sixth Circuit rejected recently a plaintiff's  claim that her employer should have interpreted her statement that she was not coming back to work and her one line  "I am resigning" letter as a request for FMLA leave.  Obviously ascribing the plain meaning to the plain words used by the plaintiff to communicate her resignation,   the court said that the plaintiff's contention  "rings hollow."   To paraphrase Alice, words can mean many things, but  "I am resigning" is not a request for  FMLA leave.  Miles v. Nashville Elec. Serv. (6th Cir. May 19, 2013).

The employee had taken a month long medical leave.  Upon her return from leave, she provided a doctor's note stating that she could return to work without restriction.  On plaintiff's  first day back to work, her supervisor granted her request to leave early.  The next morning, the plaintiff called her supervisor and said she was not coming back to work.   That same day, she gave her supervisor the one-line resignation letter.