To prevent the telecast from running late, the Academy enforces a strict 45-second limit for acceptance speeches. After 45 seconds, the 'play-off' music begins to signal the winner to leave the stage. This rule was heavily reinforced in 2010 to curb the 'grocery list' style of thanking every single agent and assistant. The catalyst for the time limit is often cited as Greer Garson’s 1943 speech; after winning Best Actress for 'Mrs. Miniver,' she spoke for nearly 6 minutes, which remains the longest speech in history. Today, the Academy encourages winners to give their 'thank you' lists to a 'Thank You Cam' backstage for the website, while using their stage time for more personal or impactful messages.