---
title: "Pattern IDs"
url: "https://commonwaysystem.org/guide/pattern-ids/"
description: "What each part of a Commonway System Pattern ID means, the nine Scale prefixes, and what the status badges mean."
updated: "2026-10-15"
---

# Pattern IDs

Every pattern in this guidebook carries a unique ID, shown on its Pattern ID card as described on the [How to Read a Pattern](https://commonwaysystem.org/guide/how-to-read-a-pattern.md) page. This page explains what each part of that ID means, why it's structured the way it is, and what the status badge next to it tells you.

## The ID format

Every pattern ID follows a fixed format:

**`[PREFIX]-[CTXCODE]-[##]`**

For example, `LOC-BBG-12`, with an optional trailing `(DENSITY)` suffix once more than one page exists for the same Typology at different density tiers.

-   **PREFIX** encodes Scale, covered in full below.
-   **CTXCODE** is a short mnemonic for the specific Typology. `BBG` stands for Bicycle Boulevard / Neighborhood Greenway, for example. `DEF` is reserved for each classification's baseline default entry.
-   **\[##\]** is a two-digit number assigned once, in the order the pattern was added to the guidebook. It never changes later, even if the pattern's position in the Pattern Index does.

## Scale prefixes

PREFIX is where the ID encodes Scale, one of nine values:

| Prefix | Meaning | Scale |
| --- | --- | --- |
| `NET` | Network | Network |
| `CDR` | Corridor | Corridor |
| `LOC` | Local | Segment/Intersection |
| `COL` | Collector | Segment/Intersection |
| `ART` | Arterial | Segment/Intersection |
| `FRE` | Freeway | Segment/Intersection |
| `INT` | Intersections & Crossings | Segment/Intersection |
| `FAC` | Facility | Facility |
| `ELM` | Element | Element |

Network, Corridor, Facility, and Element each get exactly one flat prefix, with no further subdivision. Segment/Intersection is the one Scale that subdivides, into five prefixes, because Functional Classification carries real design implications, speed, modal hierarchy, that the other four Scales don't yet have an equivalent for. That's also why every pattern page live in the guidebook today is a Segment/Intersection pattern: `LOC`, `COL`, `ART`, `FRE`, or `INT`.

See [Scale Hierarchy](https://commonwaysystem.org/guide/scale-hierarchy.md) for what each of the nine Scale prefixes actually covers, and [Street Types & Classifications](https://commonwaysystem.org/guide/street-types.md) for what each Functional Classification and Typology means in plain language.

## Status badges

Every pattern carries a status, shown as a small badge next to the classification label on the Pattern ID card.

-   **Recommended** is the quiet default, no color emphasis, since it's the unremarkable normal case.
-   **Situational / Discouraged** reuses the amber warning color, meaning the pattern is real but fits only certain contexts.
-   **Avoid** reuses the rose danger color, meaning the Commonway System actively recommends against it.
-   **Descriptive** uses a cool slate-blue, meaning the pattern documents an existing condition rather than weighing a design choice, such as [Organic / Irregular](https://commonwaysystem.org/patterns/network/organic-irregular.md) (NET-ORG-04).

## How this connects to the rest of the guidebook

See [Bicycle Boulevard / Neighborhood Greenway](https://commonwaysystem.org/patterns/local-streets/bicycle-boulevard.md) for a full worked example of a Pattern ID card in context, and the [Pattern Index](https://commonwaysystem.org/patterns.md) for every pattern currently in the guidebook.