Prior to 1977 only players who had completed the Stanley Cup playoffs were eligible. Today, players appearing in 41 regular-season games or one Stanley Cup Final game for the championship team have their names engraved on the Cup. The NHL makes exceptions for players who do not meet the standard because of injury or other extenuating circumstances.
That's why Jiri Slegr was the luckiest guy in the NHL in the spring of 2002. Acquired by Detroit at the trade deadline, he played just eight regular season games as a Red Wing and did not dress for a single playoff game for the first three rounds. But he was called on to play game five of the Stanley Cup Final in place of Jiri Fischer, who had to serve a one-game suspension. So Slegr got his name on the Stanley Cup, and has a nasty Fischer cross-check to thank for it.
Besides eligible players, the names of coaches, management and staff of the winning team are also engraved on the Cup.
It takes 13 years to fill a ring on the Stanley Cup. When a ring is full, an older ring is removed from near the top of the Cup and put on display at the Hockey Hall of Fame.
Only one name has been added against the rules. When the Edmonton Oilers won their first championship in 1984, owner Peter Pocklington included his father's name - "Basil Pocklington" - among the names engraved. It was later scratched out with a series Xs.