Proposed resolution:

Change the current wording of [string.conversions] p. 15 to:

Returns: eEach function returns a wstring object holding the character representation of the value of its argument that would be generated by calling wsswprintf(buf, bufsz, fmt, val) with a format specifier fmt of L"%lld", L"%ulld", or L"%f", respectively, where buf designates an internal character buffer of sufficient size bufsz.

[Hint to the editor: The resolution also adds to mention the name of the format specifier "fmt"]

I also would like to remark that the current wording of it's equivalent paragraph 7 should also mention the meaning of buf and fmt.

Change the current wording of [string.conversions] p. 7 to:

Returns: eEach function returns a string object holding the character representation of the value of its argument that would be generated by calling sprintf(buf, fmt, val) with a format specifier fmt of "%lld", "%ulld", or "%f", respectively, where buf designates an internal character buffer of sufficient size.