The original MQM-Full error typology from QT LaunchPad project can be accessed on the Wayback Machine.
Depending on the implementation context, implementers might need more granularity or less than is present in the MQM Core typology. If so, they can adapt the error typology to the level of granularity needed. A leaner set of error types might “roll up” the subtypes for a given dimension and mark all errors related to those subtypes simply under that high level dimension. Or, if an increased level of granularity is desired, implementers can turn to MQM-Full (the full error repository linked to above) to add the error subtypes that suit their purposes. For instance, instead of identifying all grammatical errors under the error type “grammar”, it could be desirable to identify Gender, Word form, Part-of-speech, Verb tense, and Agreement. When adapting the error typology in either direction, it is important to respect the hierarchical structure of MQM, for purposes of comparison.
The “Custom” dimension can be used for values not covered by MQM-Full and its subtypes. Or, for instance, if implementers want to annotate extra-segmental categories such as Cohesion and Coherence explicitly, they could be annotated here, with the understanding that these aspects can be orthogonal to the standard annotation.