The journal marks or fitment codes are an interesting facet of combloc style manufacturing QC. The codes are stamped on the barrel after it has been forged, externally machined, and sized. They indicate whether the component journals measure undersize or oversize relative to the target dimensions of those journals. An appropriately undersize or oversize barrel component (often marked with a matching number) would then be installed.
In essence instead of just getting the dimensions spot on every time, such as is possible with modern computer controlled tooling, the factories were simply prepared to compensate for poor dimensional control.
Newer WASR barrels are made on modern Steyr computer controlled forges and CNC lathe (Cugir had a few videos showing them off at one point ) and you generally don't see the codes on the barrels any longer, unless it's on one of the older WASRs that were basically rearsenaled military AKMs from the cold war years.