The classes are not sealed off from one another. Insurance Code § 6002.154 sets out which may act as which, in three short sentences that are easy to read past. A fire alarm technician may perform or supervise monitoring. A fire alarm planning superintendent may act as a fire alarm technician or a residential fire alarm superintendent. A residential fire alarm superintendent may act as a fire alarm technician. Those are the substitutions, and there are no others in either instrument.

Read them together and the shape is a one-way ladder. The planning superintendent stands at the top and can occupy two other classes; the residential superintendent can occupy one; the technician gains monitoring but nothing else. Nothing runs the other way: no provision lets a fire alarm technician act as a superintendent of either kind, and none adds the planning verb to a class that lacks it. Note what the list does NOT withhold — a residential fire alarm superintendent acting as a fire alarm technician takes that class as it stands, and the fire alarm technician license carries no property limit, so those verbs do reach commercial systems. What stays residential is the planning half of the superintendent’s own class. The absence is the rule here — this is a closed list, and a firm cannot infer a substitution the statute does not grant because the licensee is experienced or the property is small.

One class carries a restriction rather than a substitution, and it is the sharpest sentence in § 6002.154. A RESIDENTIAL FIRE ALARM TECHNICIAN may only provide direct on-site supervision to an employee of a registered firm for work performed under the chapter IN A SINGLE-FAMILY OR TWO-FAMILY DWELLING. Two things follow. This class can supervise, which not every reader expects of a technician-level license. And its supervision authority carries the same residential boundary its work does, so a residential fire alarm technician cannot be the supervising licensee on commercial work even though 28 TAC § 34.616 lists that class among those whose direct on-site supervision satisfies the installation and servicing requirement. The rule names the class; the statute bounds where it may act.