---
id: R4.b
family: GR-VAL
level: core
profiles: [storage-api]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/gr-val/r4-b
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# R4.b — Exposure names are unique per side

*GR-VAL (Part I) · level: core · profiles: storage-api · added in 1.0*

## The rule

> **Normative.** This is the rule.
>
> 1. Workflow exposure names must be unique within a side.
>
> 2. Inputs and outputs are independent, so one name may appear once as an input and once as an output.
>
> 3. A repeat within one side is refused with `R4_NAME_DUPLICATE` at `schema.{side}.{index}`.

## Related rules

- Names: R4.a
- Referenced by: R4.a, R4.d

---

Rule identifiers are permanent and are never renumbered. This specification carries
no implementation status: each implementation publishes its own standing against
these rules. Licensed CC BY 4.0.