The standards of inclusion for nelogisms are often high.[0] For older terms, you usually only need a few attestations.[1] It also highly depends on what corpora

The standards of inclusion for nelogisms are often high.[0] For older terms, you usually only need a few attestations.[1] It also highly depends on what corpora the dictionaries are using, since the past set can include the surviving written word, while the more modern words would require wading through the firehose of the internet, unless that term also starts being used in print publications. [0]: If I had to guess why, because dictionaries don't want to seem like they're trying too hard to be trendy by including every new slang term, instead of the most popular, and it's also hard to foresee whether any of the words will even have staying power in a year since a lot of it can be short-lived. [1]: Sometimes only one: https://en.wikipedia.org/wiki/Hapax_legomenon https://en.wikipedia.org/wiki/Hapax_legomenon