Transform rule syntax clarifications

[Kip Cole via CLDR-Users]

I’m implementing the transform rules and would appreciate a few confirmations or corrections:

Ι ($glower $ddot?) $rough → H | ι $1 ;
The "$ddot?” Is interpreted as “optional $ddot”
in the usual regex meaning

$accent_minus = [[$accent]-[$iotasub$macron]];
The “[[..]-[..]]" is regex character set negation?

$notAbove = [[:^ccc=0:] & [:^ccc=230:]];
The “[[..]&[..]]" is regex character set intersection?

| $1 $iotasub ← ($evowel $macron $accentMinus *) i ;
That the “*” here is “zero of more times $accentMinus” in the
usual regex meaning? And “$1” is the capture result in the usual regex 
meaning too?

t ($notAbove+) ̈ ; # ARABIC LETTER TEH MARBUTA
The “+” is the usual regex meaning of “one or more times”

Many thanks, —Kip

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