To visit in order to see how someone is doing.
To verify a person's information and record their arrival, such as at a hotel, airport, etc.
To integrate new revisions into the public or master version of a file in a version control system.
To announce or record one's own arrival at a hotel, airport etc.
To contact another person in order to keep the other person informed of one's situation.
To return (a book to a library, source code to a repository, etc.).
To enter solitary confinement at one's own request for protection from other prisoners.
To send somebody to solitary confinement; to make somebody be admitted to solitary confinement.
To arrive casually at a place.
To come in an unstoppable flow.
To pot with minimal force.
To come in (to a station, yard).