Facebook’s IPO paperwork answers many outstanding questions about the social-networking firm: Who its major shareholders are, how much revenue it has raked in and what it sees as its risk factors.

But it also reveals the firm’s plan in the unlikely event that its 27-year-old chief executive Mark Zuckerberg were to die. Here’s how the filing describes the arrangement:

“In the event that Mr. Zuckerberg controls our company at the time of his death, control may be transferred to a person or entity that he designates as his successor. As a board member and officer, Mr. Zuckerberg owes a fiduciary duty to our stockholders and must act in good faith in a manner he reasonably believes to be in the best interests of our stockholders.”

Zuckerberg owns less than a third of the company’s shares. However, as a result of proxy arrangements, he has 56.9 percent of the voting power. In other words, Zuckerberg has a great deal of control over the fate of his firm, thereby making a succession plan critically important.

It’s anyone’s guess whose hands he might leave Facebook in, but some details in the S-1 filing offer clues as to who his close confidants are.

It’s also worth noting that the S-1 filing says that Zuckerberg personally selected Washington Post Chairman Donald E. Graham and Marc L. Andreessen as his designees on the board of directors.

In 2009, the filing says that two million shares of common stock were awarded to “a family member of our CEO.”

And the document states that his sister, Randi Zuckerberg, earned a total of $357,864 from Facebook while she was employed there from 2009-2011.

More from The Washington Post:

Facebook files for IPO worth $5 billion

Will Facebook list on NYSE or Nasdaq?

Could Silicon Valley see a ‘Facebook effect’?