Clarify writing mode for romanization annotations

[r12a]

3.3.1.1 Indicating the Pronunciation for Chinese characters
http://w3c.github.io/clreq/#h-indicating_pronunciation_for_chinese_characters

Due to the characteristics of the Latin alphabet, such annotations appear in horizontal writing mode only.

This is a little vague, and, without careful reading, appears to contradict the picture in the following subsection of latin annotations being used in vertical text for bilingual annotations. It also contradicts the opening sentence of 3.3.2. Clearly latin text can be used alongside vertical chinese in some situations.

How about saying the following:

The horizontal nature of the Latin script results in a convention that romanized annotations representing pronunciation are usually only used alongside horizontal Chinese text.

Or we could remove the mention of latin script characteristics altogether, and say:

Romanized annotations representing pronunciation are usually only used alongside horizontal Chinese text.

To make things clearer still, we could add another sentence immediately after saying:

(Latin script used for bilingual annotations or interlinear comments, on the other hand, may well be associated with vertical text.)

I would break the paragraph at that point.

3.3.4.1 Basic Requirements
http://w3c.github.io/clreq/#h-basic-requirements

The first sentence needs to read

Romanization is normally only available in horizontal writing mode

otherwise it contradicts the second point, which says

In special cases where Romanization is needed in vertical writing mode ...

[r12a]

3.3.4.2 Characters as the Basic Units for Annotating Pronunciation
http://w3c.github.io/clreq/#h-characters_as_basic_units_for_annotating_pronunciation

The phonetic annotations are always on the top.

This again appears too dogmatic, since it is contradicted in the case of Figure 8.

[xfq]

In case other people find it confusing, the "Figure 8" mentioned above is now Figure 9:

Figure 9 An example of positioning for both Romanization and Zhuyin 拼注音共同标注排版示例。 拼注音共同標注排版示例。

Link: https://w3c.github.io/clreq/#phonetic-in-both