Right now, using -d DISPLAY on Windows causes nothing but trouble.
-t / --tty is not specially useful either:
C:\emacs> emacsclient -t
emacsclient: could not get terminal name
Feel free to ifdef away that one as well.
Just like the -d option, I think it can stay.
For what purpose? I think it's wrong to advertise (by --help) options
that don't work or, worse, cause trouble.
These are options that simply fail to work.
Right, so why have them?
On the off chance that the w32 emacsclient manages to talk to a cygwin
emacsserver that does understand -d and -t.