白衣故人青衫旧人
[bái yī gù rén qīng shān jiù rén]
In China's traditional culture, white clothing (bai yi) usually refers to scholars and literati, implying refined, pure or noble qualities; Blue robe (qing shan), on the other hand, is often related to the image of ancient officials and may also symbolize maturity and steadiness. Thus this username could be translated as 'A former friend in a white dress and an old acquaintance in a blue coat.' This nickname implies meeting an old-time friend, suggesting a kind of nostalgia or recollection for the past time.