# CMP-USECASE-ENUM — Use case must be a recognised TCR value

> The declared use case must be one of the recognised TCR use-case values.

- **Rule ID:** CMP-USECASE-ENUM
- **Layer:** Campaign (`CAMPAIGN`)
- **Checks:** `campaign.usecase`
- **Severity:** BLOCKING — Breaking this rule gets the submission rejected outright.
- **When it bites:** Gates approval — get this wrong and registration is refused
- **How it is detected:** Deterministic (settled in code from the submitted values)
- **Fix type:** Fix the field — a better value in the form clears it
- **Required by:** TCR, Twilio, Bandwidth, AWS
- **Applies:** Applies to every 10DLC registration.
- **Canonical URL:** https://ekas.io/rules/10dlc/campaign/cmp-usecase-enum/

## Why this rule exists

The use case drives the consent standard, the throughput granted, and the filtering applied, so an unrecognised value cannot be processed at all. Free-text or dropdown-label values coerced silently to a catch-all are worse than an error, because the campaign is then judged against rules nobody chose.

## How to fix it

Select a use case from the standard TCR list rather than typing a description. If none fits exactly, MIXED is the catch-all — but it carries promotional-grade consent obligations.

## Example of a compliant value

```text
Use case: MARKETING
```

## Common mistakes

- Silent coercion of an unrecognised value to MIXED hides the problem and changes which rules apply.

## Notes

Carries a descriptive id rather than a catalog one because no catalog row states this requirement; it is the precondition the use-case matrix rules depend on. It previously carried the id CMP-140, which belongs to an unrelated row ("read mnoMetadata.minMsgSamples per MNO") and made that row read as covered when nothing implements it.