30 four-char .com available to register

All these domains were available at time of posting too.

18RR.COM
SQ3E.COM
TDP1.COM
SL1P.COM
SG53.COM
RAJ7.COM
RU-B.COM
S1K2.COM
UC33.COM
YZ97.COM
ZO9X.COM
29CQ.COM
WE82.COM
WP4P.COM
C0WW.COM
C4SR.COM
CZF1.COM
DRX3.COM
ELU2.COM
G-VR.COM
1IPM.COM
2STA.COM
3GKL.COM
4QMU.COM
7HTG.COM
7IND.COM
80NM.COM
B3TI.COM
JMB1.COM
QSQW.COM