Consolidation of CJK component unification across different regions to reduce unnecessary characters

In hindsight, I should have created this page to consolidate all my issues for every single component that may need unification, without opening too many separate issues. Just like when Dr Lunde created a consolidation of glyphs page, but have since been largely abandoned after he left.

Over time, I will start nitpicking more details which I deem unnecessary and can be shared with as many regions as possible, without breaking the respective national government glyph standard rules too much. My general preference is towards JP-style glyph shapes with some exceptions. The purpose is to ensure that by unifying components, we can keep it under the 65536 glyph limit and have more room to add necessary glyphs in the future.

I am very well aware that some of the unifications presented here might have been discussed before (and which I didn't have the time to go through thoroughly) and could be rejected, but I am going to keep them because I would like a confirmation on whether these unifications can go ahead under the new design team from Arphic.

For now it's a very quick summary, after Chinese New Year, I will update with a (perhaps incomplete) list of affected characters to fix for each affected component, if it isn't too much to handle. Unfortunately I may not be able to provide a complete list as finding the affected component in every character is very time consuming and there are currently no tools to do that instantly.

This page will be updated regularly if I can.

For components that I believe are safe to unify without breaking the 新字形 or Taiwan/Hong Kong educational standard rules
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### 夕 component

I think having the dot (丶) touching (or at least be very close to) the ク part should be OK for the CN region.

As per the example image (will be updated soon for more characters), 夕 should be JP (marked green) for all regions, the JP version of 多 is mapped to all regions except for CN (marked yellow), which has an almost identical looking duplicate, but the top component is shifted a little bit to the right. 移 is currently mapped to JP for all regions.

For 多, I think maybe adjust the JP glyph to move the top component a tiny bit to the right and then remove the CN glyph.

For 名, I suggest to adjust the CN glyph, the 夕 part, so the dot can touch the ク part, and in turn match the balance of the JP aesthetic.

### 死 component

Unlike the other components which I prefer JP forms, the CN form is what I prefer, with 匕 touching the topmost horizontal line (circled in red). If it can be unified, adjust the JP glyphs so that 匕 touch the the topmost horizontal line (with no serif detail), and then maybe adjust the 丿 part of 匕 to lower it a bit like the CN glyph as per the A15 remarks from #155, and then remove the redundant CN glyphs.

Alternatively, an easier way would be to remove the JP glyphs and assign the CN glyphs to the JP and KR glyphs if unifiable, but I strongly prefer the JP balance and aesthetics though.

If the CN glyph is to be kept instead, the 夕 part would have to be adjusted as well (circled in orange, see above "夕 component").

Understandably, we cannot unify all regions as the TW standard demands a more horizontal stroke for 匕.

While most Japanese fonts (samples from my Mac pre-installed fonts + Creative Cloud fonts) have the 匕 separated from the topmost horizontal stroke, some (even Adobe's own Kozuka fonts by a close margin) have 匕 touching the top horizontal line.

Which is why I think it would be better if we can unify the 死 component, both with 夕 (JP style) and 匕 touching the topmost horizontal stroke.

### 冘 component

[See here.](https://github.com/adobe-fonts/source-han-serif/issues/148)

### 今 component (TW/HK regions only)

[See here.](https://github.com/adobe-fonts/source-han-serif/issues/132) I would like to also map the JP form of the 今 characters to the TW/HK versions if possible, but some other characters which contain 今 will simply have to be adjusted because the other components (the traditional printing forms of JP) cannot be used for TW/HK.

For the time being, the characters to review will be this:
今仱吟坅妗岒忴扲汵昑肣枔㲐玪矜砛紟耹䑤蚙衿訡赺趻軡鈐䩂靲䪩䰼鹶黅黔霒䶃䶖㪁欦雂鳹㕂岑庈芩笒棽琴含念侌衾貪酓霠𩃬

**LEGEND:**
Green - v1 JP glyph to be restored (忴扲汵枔蚙赺*軡靲).
Purple - v1 JP glyph that cannot be restored due to unsuitability for TW/HK use (肣紟霒欦雂庈霠).
Cyan - v2 JP glyph to replace the TW/HK glyphs (今仱吟坅岒昑玪矜耹鈐鹶黅黔鳹棽琴含念).
Orange - The TW/HK glyph to be replaced by the v1 restored JP glyph (in green) and deleted (also map the restored glyphs to JP and KR).
Red - The TW/HK glyph to be replaced by the v2 JP glyph (in cyan) and deleted.
Yellow - Adjust TW/HK glyph to match JP aesthetics (妗肣紟衿霒雂岑庈芩笒衾酓霠).
Magenta - Replace glyph currently mapped to CN with TW/HK forms for JP/KR locales (雂庈).

*However, I am not entirely sure whether the v1 JP glyph for 赺 is suitable for TW/HK as the second stroke of 今 is different.

### 侖 component
[See here.](https://github.com/adobe-fonts/source-han-serif/issues/130)

### 竹 component (TW/HK regions only)
[See here.](https://github.com/adobe-fonts/source-han-sans/issues/182#issuecomment-365598683) Apparently this was not addressed when v2 rolled around, and I suppose the suggestion was rejected, so I will bring this up again.

While I cannot suggest changes to resemble another commercial typeface, for the sake of unifying components, I have to give a reference (this is sans-serif, but my point still stands). This reference is Hiragino Sans CNS, which was updated to completely follow Taiwan MOE standards on macOS 12 Monterey after many years of being an incomplete typeface with a mix of Japanese and mainland China glyph shapes. Basically put, the 竹 component in Hiragino Sans CNS is exactly the same as the GB (China) and the Japanese version.

### 亙 component (TW/HK regions only)
[See here,](https://github.com/adobe-fonts/source-han-sans/issues/315) but this one is for Serif.

The characters to review are:
亙恆絚䱍揯㮓緪堩䱭

I suggest removing these TW/HK glyphs and mapping them to CN (coloured in yellow): 亙 (HK only), 絚, 堩, 䱭

For components that are potentially controversial and might break the 新字形 or Taiwan/Hong Kong educational standard rules
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### 辶 component
[As our good friend said](https://github.com/adobe-fonts/source-han-sans/issues/300), but to summarise, unifying with the JP form (circled in green) can potentially save quite a bit of CIDs and it isn't gonna be much of a difference to the naked eye. However, while I can't describe it well, it appears that the Chinese standard (circled in red) wants the bottom left component (circled in the 道 character) to be different from the JP form, and may be part of the 新字形 rule, even the gap thingy (circled in the 途 character).

_My apologies if my colour coding and circling is confusing. The green circles mean the JP aesthetics to unify to and the red circles mean the current CN aesthetic._

We already knew the suggestion was previously rejected, but today might be different with a new design team from Arphic.

### 八 component
The Song-style detail which I circled in the below pic, I don't think it's necessary. That could be unified with the JP style glyph without much of a fuss, but to be honest, it's not going to benefit much as there won't be a lot of characters that need sharing, especially the 公 part which the bottom part must be connected for the Chinese regions, similar to handwriting.

There's an unencoded glyph called uni516BuE0101-JP (CID 61995 as of v2.001) which could be the CN/HK glyph, but pretty unlikely to materialise.

### 雨 component
[See here.](https://github.com/adobe-fonts/source-han-serif/issues/150)

### 尤 component
I lumped it with 冘 in the [same issue page](https://github.com/adobe-fonts/source-han-serif/issues/148), but the simplified Chinese fonts treat this a bit differently, with the last stroke 乚 more separated from 丿 and touching the horizontal line.

From top to bottom (all Mac fonts): Kaiti SC, Heiti SC, Lantinghei SC, SimSong (not SimSun), Songti SC, Yuanti SC

Funny enough, the Kaiti font is a bit more similar to the JP/TW/HK form, and some characters from Heiti SC also follow that, in this case the characters are all marked in green.

I am not suggesting that we follow another font, but I am making sure we have a good reference of where general Chinese fonts go in terms of glyph shape and whether we can accept a bit of the Japanese-style glyph shape for the CN region without making too much of a fuss.

**UPDATE 1 (2022-01-30?):** Added list of characters to replace in the 今 component, some minor suggestion changes to the 死 component and other miscellaneous changes.

**UPDATE 2 (2022-02-03):** Added 竹 and 亙 components. Also changed my heading to consider TW/HK standards as well.