In practical seriality (musalsal bi-l-fiʿl), successive narrators perform a particular action when transmitting the report. The action may relate to the report's content or merely to the circumstances of narration.
Example: A teacher offers dates or takes the pupil's hand while narrating, and the same action is reported at multiple stages of the chain. The action characterizes the transmission; it does not itself become a binding ruling derived from the hadith.
One teacher's single performance does not make the entire chain practically serial. The recurrence across successive levels must be demonstrated; if proven only at two stages, one should state that limited extent.