On Sun, Oct 13, 2019 at 2:35 PM Lyberta via Std-Proposals <std-proposals@lists.isocpp.org> wrote:
This paper proposes new keywords in the form iec60559_binaryN that can
be used by new types proposed in P1468.

The paper's title is "Reserve good keywords for floating-point types." But `iec60559_binary16` (which I had to reopen the PDF twice to double-check the spelling of) is 100% absolutely not a "good" keyword by any metric.  So, the paper is currently mis-titled.

I don't see any advantage to "reserving" these tokens for "future" use. Are you worried that if you don't reserve them now, somebody might use them as identifiers in real code?  If that's your concern, then you should be equally concerned that someone might already have used them as identifiers in real code; in which case, you are proposing a breaking change, and you should say so.

Rather than use `iec60559_binary16` for the new keyword, I suggest you focus on using a keyword such as `__iec60559_binary16`, and then in whatever future proposal gives it semantics, you can also propose

    namespace std {
        using float16 = __iec60559_binary16;

You don't need to "reserve" the keyword `__ie60559_binary16`, because it already lives in implementation namespace: users cannot use it as an identifier today. So, problem solved, right?