The omission in al-mursal may be evident, in which case it is al-mursal al-wāḍiḥ. Concealment and clarity here are relative, varying with the rank of the critic.
Al-mursal al-khafī is a mursal whose omission is concealed; clarity and concealment are relative, varying with the rank of the critic.
An omission from the isnād made with the intention of suggesting audition is mudallas; without that intent it is mursal.
An omission from the start of the isnād by the compiler's action — this is al-muʿallaq.
Al-mursal is an omission from the end of the isnād, after the tābiʿī; one of the four kinds of rejected report rooted in a break in the chain.