This, for those as yet unaware of such a disadvantage, refers to discrimination against those whose surnames begin with a letter in the lower half of the alphabet.

　　①Over the past century, all kinds of unfairness and discrimination have been condemned or made illegal.

　　②But one insidious form continues to thrive: alphabetism.

　　③This, for those as yet unaware of such a disadvantage, refers to discrimination against those whose surnames begin with a letter in the lower half of the alphabet.

　　参考译文：

　　①(现象：分1)在过去的一个世纪里，各种不公平和歧视被谴责或被定为非法。

　　②(转折：分2)但有一种潜在的歧视仍然盛行:字母排序歧视。

　　③(定义：总)对于那些尚未意识到这一劣势的人来说，它指的是对姓氏字母表后半部分字母开头的人的歧视。