Available four chars domains with results in the WayBack Machine

As always, all of them were available at time of posting.

SH4W.COM
ST68.COM
FOP9.COM
IP-W.NET
CDUX.NET
JROE.NET
EX6X.COM
MOLV.NET
QXBJ.NET
64OS.COM
6U78.COM
VSKK.NET
ACR2.COM
K544.COM
64OS.NET
MK75.COM
MGM9.COM
O2G0.COM
MPC3.ORG
PT-O.COM