How to position ruby and text decoration

[r12a]

If a hanzi sequence is annotated with pinyin and is also underlined, what are the relative positions for the annotation and the underline?

This question arose in relation to a CSS spec, and it would be useful to add some information about it to clreq.

[upsuper]

Pinyin is usually annotated on the top, and underline is... on the bottom, so I don't think they interact with each other?

[r12a]

Well 'usually' means not always ;-) So what should happen in those other cases?

We don't put any restrictions or give any advice on what people can do with ruby position. Should we?

[ryukeikun]

As posted in Issue #169 , this is also a rare case.
Obviously, the principle rule is the underline should not overlap the annotations.

Basically, underline is a kind of emphasize mark, and in most of case, the contents need be emphasized is the main characters but not including annotations such as pinyin, so just place the underline as the current common way both in horizontal/vertical text, and let pinyin and other annotations make enough space for the underline.

Maybe in rare cases, both pinyin and main characters needs to be underlines, but I don't think visually it is a good design.

[r12a]

The second of the pictures above shows the ruby text above as well as below the base text. Presumably, this is to avoid the need to move the base characters apart in order to fit the annotations (although that didn't appear to work in the very first line).

[1] is this a common thing to see?

[2] does it provide a way of dealing with underlines? (ie. move the annotation to the other side of the base characters from the underline, just where an underline occurs)

I doubt we need to worry about whether underlines should be drawn below both base and annotation separately – i've not seen that in Japanese, and @ryukeikun seems to be suggesting that it's not something that happens in Chinese either.

let pinyin and other annotations make enough space for the underline

Not clear to me what this means. Make the underline far enough from the base that the annotation will fit on the same side? Or move the annotation to the other side? A picture would be very useful here.