W. Clinton was a starship captain in the 24th century. Clinton was the commander of the SS Oregon.
In 2370, Clinton was listed on the Deep Space 9 arrival roster. (DS9: "Whispers", production art)
This character was only mentioned in writing.
The okudagram graphic that included this name was also populated by some other in-jokes. This character was named after William Jefferson Clinton, who was President of the United States at the time the episode aired.