$NonComm
contains a list of all noncommutative heads present.
Overview, NonCommQ, NonCommutative.
$NonComm
\{\text{DiracGamma},\text{DiracSigma},\text{GA},\text{GAD},\text{GAE},\text{GS},\text{GSD},\text{GSE},\text{LeftPartialD},\text{LeftRightPartialD},\text{LeftRightPartialD2},\text{FCPartialD},\text{OPESum},\text{QuantumField},\text{RightPartialD},\text{Spinor},\text{SpinorU},\text{SpinorUBar},\text{SpinorV},\text{SpinorVBar},\text{SUNT},\text{PauliSigma},\text{PauliXi},\text{PauliEta},\text{TGA},\text{CGA},\text{CGAD},\text{CGAE},\text{CGS},\text{CGSD},\text{CGSE},\text{SI},\text{SID},\text{SIE},\text{CSI},\text{CSID},\text{CSIE},\text{FeynCalc$\grave{ }$Package$\grave{ }$dotsimpHold},\text{FCChargeConjugateTransposed},\text{CovariantD},\text{FieldStrength},\text{QuarkGluonVertex},\text{QuarkPropagator},\text{Twist2AlienOperator},\text{Twist2CounterOperator},\text{Twist2QuarkOperator},\text{ChiralityProjector},\text{Spinor},\text{DiracMatrix},\text{DiracSlash}\}