ID_Start, ID_Continue, and stability extensions

[Whistler, Ken]

Mathias,

> > What are the “stability extensions” this document refers to?
> >
> Here are the code points that match the respective property according to
> `DerivedCoreProperties.txt`, yet don’t match these properties if you’re
> adding/removing the categories manually based on the property definition in
> TR31.
> 
> `ID_Start`:
> 
> * U+2118
> * U+212E
> * U+309B
> * U+309C
> 
> `ID_Continue`:
> 
> * U+00B7
> * U+0387
> * U+1369
> * U+1370
> * U+1371
> * U+19DA
> 
> Why these differences?

See the listings for Other_ID_Start and Other_ID_Continue in PropList.txt.
Those are your "stability extensions" for the derivation of the identifier-related
derived properties.

--Ken

# ================================================

2118          ; Other_ID_Start # Sm       SCRIPT CAPITAL P
212E          ; Other_ID_Start # So       ESTIMATED SYMBOL
309B..309C    ; Other_ID_Start # Sk   [2] KATAKANA-HIRAGANA VOICED SOUND MARK..KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK

# Total code points: 4

# ================================================

00B7          ; Other_ID_Continue # Po       MIDDLE DOT
0387          ; Other_ID_Continue # Po       GREEK ANO TELEIA
1369..1371    ; Other_ID_Continue # No   [9] ETHIOPIC DIGIT ONE..ETHIOPIC DIGIT NINE
19DA          ; Other_ID_Continue # No       NEW TAI LUE THAM DIGIT ONE

# Total code points: 12