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The HSK (汉语水平考试, Hànyǔ Shuǐpíng Kǎoshì) is a standardised proficiency test for non-native speakers of Mandarin. This deck is based on the official proficiency standard that took effect on July 1st, 2021, but please note that actual tests based on this standard have not yet been rolled out. Please see this blog post to check our guide to the new HSK: https://blog.skritter.com/hsk2021. The characters in this deck are sorted by frequency to help you learn the most important words first.