白纸黑字给勋诉不完的思念
[bái zhĭ hēi zì jĭ xūn sù bù wán de sī niàn]
Here 'Bai Zhi Hei Zi' are Chinese set words referring to something officially recorded and undeniable. This nickname 'Bai Zhi Hei Zi Gei Xun Su Bu Wan De Sikuan' is probably expressing deep missing thoughts for someone called 'Xun' in the style of serious letters, with an undying emotional connection or admiration conveyed towards 'Xun'.