Mu‘allaq: one or more links removed from the compiler's side of the chain.
Mursal: a Successor directly attributes a report to the Prophet ﷺ without identifying the intermediary.
Mu‘dal: two or more consecutive omissions at one point.
Munqati‘ (narrow usage): another overt break, such as a single middle link or nonconsecutive omissions.
Mudallas: ambiguous citation of a particular report from a teacher actually met, or obscuring a teacher's identity by unusual designation.
Mursal khafi: apparent direct citation from a contemporary whom the narrator did not meet.
Some names classify the location of the gap, some its number and consecutiveness, and others the concealed mode of attribution. Several labels can therefore overlap in a single report.