---
id: SCH-27
family: GR-SCHEMA
level: core
profiles: [storage-api, editor-client]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/gr-schema/sch-27
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# SCH-27 — A served port omits everything that matches the default

*GR-SCHEMA (Part I) · level: core · profiles: storage-api, editor-client · added in 1.0*

The wire shape is lean by divergence, which means a client cannot read absence as "unknown". Absence is the default, and the defaults are fixed here.

## The rule

> **Normative.** This is the rule.
>
> 1. A served port emits `defaultValue` only where it is not null, `exposedByDefault` only where it is false, and `displayOrder` only where it is not 0.
>
> 2. A client must read the absence of those keys as no default, exposed, and order 0 respectively.

## Related rules

- Names: SCH-8, SCH-15
- Referenced by: SCH-8, SCH-15

---

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.