[css-content] Does string-set accept <content-list>?

[Loirooriol]

The syntax of the string-set property is defined as follows:

none | [ <custom-ident> <string>+ ]#

However, lots of the examples in the spec seem to use a different syntax:

• Example 16: head > title { string-set: title contents; }
• Example 17: H1 { string-set: chapter contents; }
• Example 18: h2 { string-set: heading content() }
• Example 19: h1 { string-set: header content(before) ':' content(text); }

The problem seems that before dc01554, the syntax was

[[ <custom-ident> <content-list>] [, <custom-ident> <content-list>]* ] | none

In Named strings, the spec still says

The string-set property accepts values similar to the content property, including the extraction of the current value of counters.

But unlike attr(), defined in CSS Values, I don't think <content-list> is allowed wherever a <string> is expected.