# MISSING_POLICY — The case selects no rule for the count

## What it means

Some computations are deliberately left open by the package: how deadline
days are counted, where the count starts, what happens on holidays. The
package declares the available rules, and each case selects one. Until a
case selects, the computation has no defined meaning — counting without
the selected rule would silently pick a meaning the case never chose. The
engine reports the open choice instead of counting.

This status is about the case, not the package. The rules are fine; they
are waiting to be told which counting rule applies.

## When you see it

```law
language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

entity Applicant;
relation application_filed(a: Applicant, on: Date) kind empirical { key(a); }
relation decision_due(a: Applicant, due: Date) kind institutional;

deadline policy CALENDAR_DAYS {
    start_count next_day;
    include_end true;
    roll no_roll;
}

rule DecisionDeadline strict {
    for a: Applicant;
    for on: Date;
    when application_filed(a, on);
    then decision_due(a, add_calendar_period(on, 30 calendar_day));
}
```

```lawtest
language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

test "deadline without a policy is not computed" {
    given {
        context { legal_time @2026-03-01; decision_time @2026-03-01T09:00:00Z; knowledge_time @2026-03-01T09:00:00Z; timezone "UTC"; }
        assert application_filed(entity_ref("urn:demo:diagnostics:ann"), @2026-03-02) { origin case_input; }
    }
    evaluate truth(decision_due(entity_ref("urn:demo:diagnostics:ann"), @2026-04-02));
    expect evaluation_status == MISSING_POLICY;
}
```

The package declares how calendar days are counted, but this case selects
none of the declared rules. The due date is not computed.

## What to do

Select the counting rule in the case context and ask again. Which rule to
select is a legal choice about the case, not a technical default — the
package will not pick one for you.

## Related

- [Testing a package](/language/testing-a-package/) — how scenarios pin outcomes.
- [MISSING_INPUT](/diagnostics/MISSING_INPUT/) — when an outside input is missing instead.