Currently, the policy concerning ruby characters is not clearly stated leading in a lack of consistency in their usage.
Answers in English tend to have a lot of ruby even on common words. Indeed, adding ruby ease the reading but at the same time it is not always desirable. I even think that adding too much ruby do more harm that not adding them.
The very first reason is very pragmatic. Adding ruby takes time since we need to write the same thing twice. Thus, adding ruby is a burden to the writer.
Second, eyes tend to be attracted by the ruby more than by the character. I think that this is really harmful because if we pay more heed to the ruby than to the character the learning process of the character is badly impacted. Moreover, even if we know the reading of the characters, too much ruby will eventually dulls our skills. Because there is no point knowing the reading if those readings are always shown.
Therefore, I would suggest that we agree on a set of rules concerning ruby. I propose the following initial set of rules and I would like your opinion on them.
- Adding ruby is at the discretion of the writer;
- Uncommon 当て字, 難読 and uncommon 表外字 should have ruby;
- common words 常用漢字 should not have ruby.
The first rule seems capital to me, after all we are free to write whatever we want as long as it is useful. Rules 2. & 3. are more addressed to edits, if we see an uncommon word, a word with an irregular reading or a rare character then we should suggest an edit. But in all other cases, I think it is better not to add to many ruby.