[css-counter-styles] case sensitivity of counter-style-name

http://dev.w3.org/csswg/css-counter-styles/#the-counter-style-rule says:
Counter style names are case-sensitive. However, the names defined in this
specification are ASCII lower-cased on parse wherever they are used as
counter styles, e.g. in the list-style set of properties, in the
@counter-style rule, and in the counter() functions.

Does it mean, counter style names should normally be case-sensitive except
the names defined in this spec? I think this rule is puzzling.

http://www.w3.org/TR/2011/REC-CSS2-20110607/syndata.html#characters says:
All CSS syntax is case-insensitive within the ASCII range (i.e., [a-z] and
[A-Z] are equivalent), except for parts that are not under the control of
CSS.

According to this rule in CSS2.1, I believe all counter style names,
instead of only the predefineds, should be case-insensitive and ASCII
lower-cased on parse.

- Xidorn