clarify quotation rules for level 1

[bertsky]

I can only find this short statement about quotation in level 1:

Quotation marks are transferred to today's use and are not differentiated

Considering the many differentations offered by today's use in Unicode, also listed in full by the spec, I wonder what that means.

Today could mean only the the ubiquitous ASCII reduction, i.e. only " and '. That would mean the differentiation is reserved for levels 2 and 3.

But it could also be a subset (e.g. no "low-9" or "high-reversed-9" or no angular quotes).

Could someone please clarify here and update the specs accordingly?

[tboenig]

• The Levels are a mirror of text normalisation or interpretation.
• With "Today" means the usage in the community or in the transcription tradition.
• In some cases, they have text with different quotation marks. These marks would normalise or reduced to few marks in Level 1.