obsolete terms, and specialized jargon words are allowed if they meet all other criteria for acceptability, but archaic spellings (e.g. NEEDE for NEED) are generally not allowed. Foreign words are not allowed in English-language Scrabble unless they have been incorporated into the English language, as with PATISSERIE, KILIM, and QI. Vulgar and offensive words are generally excluded from the OSPD but allowed in club and tournament play, but in 2020, the rise of anti-racism protests caused trademark owners and lexicon compilers to exclude words deemed to be personally applicable offensive slurs, resulting in their expurgation, while retaining other offensive words. Proper nouns and other exceptions to the usual rules are allowed in some limited contexts in the spin-off game Scrabble Trickster. Names of recognized computer programs are permitted as an acceptable proper noun (for example, WinZip). The memorization of two-letter words is considered an essential skill in this game. There are two popular competition word lists for English-language Scrabble: NASPA Word List (NWL, also known as OTCWL, OWL, or TWL) Collins Scrabble Words (CSW, also called "Collins" or "SOWPODS") The first predominates in the U.S., Canada, Israel and Thailand, and the second in English Scrabble in the rest of the world. There is also a large community of competitive Collins players in North America, with its own NASPA rating system. NWL and OSPD Today's NASPA Word List, published by NASPA Games, descends from the Official Tournament and Club Word List (a non-bowdlerized version of the Official Scrabble Players Dictionary) and its companion Long Words List for longer words. The current version of NWL is NWL2020, effective January 2021, and the Official Scrabble Players Dictionary, published by Merriam-Webster, is currently in its sixth edition of 2018. NWL includes all current OSPD words, plus several hundred offensive words and genericized trademarks such as KLEENEX; as of 2020, it no longer includes words judged to be personally applicable offensive slurs. The NWL and OSPD are compiled using a number of major college-level dictionaries, principally those published by Merriam-Webster. If a word appears, at least historically, in any one of the dictionaries, it is included in the NWL and the OSPD. If the word has only an offensive meaning, it is included only in the NWL. The key difference between the OSPD and the NWL is that the OSPD is marketed for "home and school" use, without words which their source dictionaries judged offensive,