This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 110c. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
[Adopted at the February, 2019 meeting as part of paper P1041R4.]
The resolution of issue 1802 clarified that char16_t string literals can contain surrogate pairs, in contrast to char16_t character literals. However, there is no explicit requirement that char16_t literals be encoded as UTF-16, although that is explicitly stated for char16_t character literals, so it's not clear what the value is required to be in the surrogate-pair case.
Rationale (February, 2019)
The Standard is now clear on this point.