Why is the affixal 子 treated specially when abbreviating people’s names?

Question

Often, names are abbreviated using the initial letter in romanization, or some random letter, like "A". However, when the name has an affixal 子, that part is often left, like "A子". I have not seen any other character been treated like this. For example, I have not seen "A果", "A史", "A美", "A明", "A郎". Why is "子" treated specially?

Someone might answer that it is to indicate that the person is female. For that kind of answers, it means that the custom (not the answer) is based on prejudice and sexual discrimination for thinking that people's gender can be identified by the name and that "子" means female, and I would have further questions:

• Why don't they write the gender normally (explicitly) instead of trying to tuck that information into the abbreviated name?
• Why is it necessary to indicate that the person is female just when the name ends with "子"?
• Why is it not necessary to indicate that a person is male?
• What happens for males whose name end with "子"?

And of course, I appreciate other kinds of answers as well.

Answer 1

I think that it is rare to use the words such as A子 and B子 as an abbreviation. They are placeholder names for females, and they do not usually mean that the names actually end with 子. Just like suffix 子, suffix 男 (such as A男) is often used to make placeholder names for males. (Here is a random example which uses A男 and B子.)

Some people use letters with 子 for females and letters without a suffix for males. I do not know the exact reason. (Maybe in older time, a person was assumed to be a male by default?)

Because they are not formed by abbreviation, if one refers to a male whose name ends with 子, it will be A男, not A子.