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The key word here is the word "process". Transliteration should be systematic. Ideally anyone transliterating should produce the same result. Typically it follows an ISO standard or government legislation. This may then be simplified in some way. For example, the Chinese example in https://icann-community.icannatlassian.orgnet/wiki/displayspaces/tatcipdp/pages/107808386/Chinese+Addresses has the tone marks, that according to the Chinese transliteration rules should be there, removed.
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