Rule 5 Draft Explanation

For those who were a little confused...

From ESPN.com:
The Rule 5 draft


First off, note that it's not the "Rule V Draft," but the Rule 5 draft. It's
called the Rule 5 draft because the section of the Official Rules that
covers the draft just happens to be Rule 5 in the book.

Eligibility: A player not on a team's Major League 40-man roster is eligible
for the Rule 5 draft if: the player was 18 or younger when he first signed a
pro contract and this is the fourth Rule 5 draft since he signed, OR if he
was 19 or older when he first signed a pro contract and this is the third
Rule 5 draft since he signed.

A player drafted onto a Major League roster in the Rule 5 draft must remain
in the majors (on the 25-man active roster or the DL) for all of the
subsequent season, or the drafting club must attempt to return him to his
original club. However, since a returned Rule 5 player must first be placed
on outright waivers, a third club could claim the player off waivers. But of
course, that club would then also have to keep him in the majors all season,
or offer him back to his original club.

Occasionally, the drafting club will work out a trade with the player's
original team, allowing the drafting club to retain the player but send him
to the minors.