This is the type of an element in a noncommutative graded ring. One can deal with these elements in much the same way as in the commutative case. See RingElement for details.
The object NCRingElement is a type, with ancestor classes HashTable < Thing.
The source of this document is in /build/reproducible-path/macaulay2-1.25.05+ds/M2/Macaulay2/packages/NCAlgebra/NCAlgebraDoc.m2:1115:0.