If I buy a crude oil futures contract at CME, must I sell the contract before the last trading day?

External question — Personal Finance Stack Exchange Author: William Original post: https://money.stackexchange.com/questions/124784 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Does CME have different contracts for different traders, i.e., some traders must close their positions before the last trading day of their futures contracts while others can hold their position to receive real crude oil? If so and I'm the former type of trader but does not close my position myself at the last day, at which price and at what time will CME close my position for me?