Interpretive rule: what it binds, and what it only predicts

An interpretive rule is a government agency telling you, in advance and in public, how it reads a statute it has to apply. That is all it is. It does not add a duty to the statute, it does not make lawful conduct unlawful, and on its own it binds nobody. What it does is remove the surprise: when the agency decides a case, these are the things it has said it will be thinking about.

The distinction matters on an import desk for one reason. The demurrage argument the whole category runs on, that a charge which could not have changed anybody’s behaviour is a weak charge, comes from an interpretive rule, and a letter that cites it as though it were a prohibition is citing the wrong instrument at the carrier.

Which FMC rule is which

The Federal Maritime Commission has two sets of words in the Code of Federal Regulations on demurrage and detention, and they do different jobs.

46 CFR part 541 is the billing rule. It says a demurrage or detention invoice “must be accurate and contain sufficient information”, and then lists the minimum fields in four groups: identifying, timing, rate and dispute information. Then it states a consequence:

Failure to include any of the required minimum information in this part in a demurrage or detention invoice eliminates any obligation of the billed party to pay the applicable charge.

That is a binding rule. There is a duty, there is an addressee, and there is an effect if the duty is not met. If a field is missing, the charge is not owed, and you are not arguing about reasonableness at all.

46 CFR 545.5 sits in a part titled “Interpretations and Statements of Policy” and opens by saying what it is for:

The purpose of this rule is to provide guidance about how the Commission will interpret 46 U.S.C. 41102(c) and § 545.4(d) in the context of demurrage and detention.

Guidance about how the Commission will interpret a statute. The prohibition on unjust and unreasonable practices lives in the statute, 46 U.S.C. 41102(c). 545.5 is the Commission’s published account of how it reads that prohibition when the subject is a storage or equipment charge.

One thing that does not separate them, and is worth knowing because it looks as though it should: both parts begin their authority citation with 5 U.S.C. 553. The citation line is not the tell. The text is.

Read the verbs

Run through 545.5 and count the verbs that address a carrier. There are none.

What there is instead, paragraph after paragraph, is the Commission describing its own future reasoning. On the incentive principle, which is the heart of the rule: “the Commission will consider the extent to which demurrage and detention are serving their intended primary purposes as financial incentives to promote freight fluidity.” On cargo availability: the Commission “may consider … the extent to which demurrage practices and regulations relate demurrage or free time to cargo availability for retrieval.” On notice, on government inspections, on dispute policies, on terminology. May consider, may consider, may consider.

Exactly one sentence in the rule makes a prediction about an outcome, and it is the one worth memorising:

Absent extenuating circumstances, practices and regulations that provide for imposition of detention when it does not serve its incentivizing purposes, such as when empty containers cannot be returned, are likely to be found unreasonable.

“Likely to be found.” Still not a prohibition, but it is the Commission saying, in advance, which way it expects to come out. A refused or unavailable empty return appointment is therefore the strongest single fact an importer can have in the file, and it is strong because of this sentence rather than because a rule was broken.

And paragraph (f) closes the door on reading the rule as a checklist. Headed Non-Preclusion: “Nothing in this rule precludes the Commission from considering factors, arguments, and evidence in addition to those specifically listed in this rule.” You cannot satisfy 545.5. You can only know what it has told you it cares about.

What this changes about a dispute

Three practical consequences, in the order they come up.

Cite the right instrument. A missing field is part 541 and the charge is not owed. A charge that accrued while nobody could have collected the box is the statute, read the way 545.5 says the Commission reads it. Those are two different letters with two different asks, and merging them weakens both. The route for the second is a charge complaint.

The evidence 545.5 asks for is evidence about you. Look at what it lists under notice of cargo availability: the Commission may consider “the type of notice, to whom notice is provided, the format of notice, method of distribution of notice, the timing of notice, and the effect of the notice.” Not one of those is a document the carrier will hand over. They are facts about what reached your desk and when: which email, to which address, at which hour, and what happened next. A desk that can produce that, dated, is arguing on the ground the Commission chose. A desk reconstructing it from memory three months later is not.

An interpretive rule can move. Part 541’s billing duties were made by a rulemaking and would take another to change. A published interpretation is the agency’s own reading, and agencies revise their readings. So the right way to hold 545.5 is as the current statement of how the Commission thinks, checked when it matters, rather than as a permanent feature of the trade. Which is also why the carrier’s tariff and your own file are the things to keep, because they are yours.

Where Docket sits

Docket does not write dispute letters and does not advise on whether a charge is reasonable. That is a decision for the Commission, or for whoever you retain.

What it does is keep the file that 545.5’s own list asks for. Every notice, in the channel it arrived on, with the hour it arrived. Every chase that went out and every one that was not answered. The date the cargo became available against the date the pack was complete. Each of those is a line in the audit trail rather than a reconstruction, which is the difference between an argument and a recollection.

That is the whole reason to want demurrage and detention software that keeps the dated record: not because a tool can make a charge unreasonable, but because the rule the Commission published tells you exactly which dates somebody will ask you for.