Related smells: No Subsystems, Insufficient Modularization, Insufficient Modularization
A variant of the well-known Insufficient Modularisation smell, ported to grammars: if the size of a grammar is much larger than expected, the time has come to split it up in modules. Old-fashioned notations did not have any explicit modularisation capabilities and treated a collection of production rules as a set, but modern language workbenches have advanced frameworks with namespaces, dependence management, etc [SLE-2013-ErdwegSVBBCGHKLKMPPSSSVVVWW] [BastenB0KLLPSV15].