Twelver Shia doctrine requires an unqualified believer to identify and follow the most learned living marja available, a determination called taqlid, and manuals exist within the tradition describing how a lay Shia Muslim is meant to establish which candidate is most learned, generally by consulting the assessments of other qualified scholars rather than by personal judgement, since the ordinary believer is by definition not equipped to evaluate legal scholarship directly. Once a follower has chosen a marja, the practical relationship runs through that marja's risalah, a published manual of rulings covering prayer, fasting, transactions, family law and much else, which the follower consults for guidance on ordinary religious and legal questions.
The mechanics of this relationship have moved substantially online in recent decades, with the offices of major marjas, including those based in Najaf and Qom, maintaining websites and, more recently, mobile applications through which followers anywhere in the world can search rulings, submit questions and receive answers, extending a relationship that once depended on physical proximity to a teacher or a printed manual into an instantaneous global one, without changing the underlying religious requirement that the follower submit to a specific named, living authority rather than to a body of law in the abstract.