AL Standards

---
name: al-standards
description: The OnlyCopilotFans (OCPF) AL Development Standards Guide for Microsoft Dynamics 365 Business Central - coding standards, API page design, field inclusion, naming and abbreviations, object ID allocation, gap analysis, anti-patterns, multilanguage/XLIFF rules, upgrade code, events, and the client page rules for parent–child pages and number series. Use when writing, reviewing, or planning Business Central AL code or API pages; when writing a list part, subform, related-record list, setup page, or assisted setup wizard; when a number-series field has no lookup or "The view is filtered, and the entry is outside the filter" appears; when the user asks to "check this AL against OCPF standards", or when an OCPF runbook needs its Standards Guide and GitHub isn't reachable.
---

# OCPF AL Development Standards Guide

The full guide is in [`references/ocpfALDevStandardsGuide.md`](references/ocpfALDevStandardsGuide.md),
bundled with this plugin from the guide's own repository,
<https://github.com/ajansari/ocpfBCALStandards>, at the release tag the framework pins (`v1.13.1.0`
for runbook v6.0.0.0; the pin is named in the framework's `standardsGuide/README.md`). Its version is
on its own `**Version:**` line.

## When a project follows the OCPF runbook

The runbook fetches the guide at the pinned tag from `ajansari/ocpfBCALStandards` into the
project's `ocpfFramework/standardsGuide/` folder at its first step (Full PRE-01, Lite Step 1), with
the framework's prelude `README.md` beside it. That fetched copy is the one to use. Use this
bundled copy only as the runbook's fallback when GitHub isn't reachable. In that case:

1. Copy `references/ocpfALDevStandardsGuide.md` into `ocpfFramework/standardsGuide/` in the project root.
2. Write `ocpfFramework/standardsGuide/SNAPSHOT.json` with `"source": "ocpf-bc plugin bundle"`, the plugin
   version, the guide's version, and the timestamp.
3. Tell the human plainly that the bundled copy was used, naming its version, and that the runbook
   will refresh it from GitHub when asked.

## When there's no runbook (a quick review or question)

Read the relevant part of the guide and apply it. Cite rules as **Standards §<number>** so the
human can look them up. The guide is organized into Parts 1–11 and Appendices A–E; start from its
table of contents rather than reading the whole file. Part 11 holds the two client page rules that
recurred most on real projects — the parent link on child pages (§11.1) and number-series fields
(§11.2) — with the sandbox checks that prove them (§11.3).

- Where a rule depends on project parameters (publisher, prefix, namespace, ID ranges), the guide
  defers to the project's parameters. Ask for them rather than guessing.
- For Base App facts (table numbers, fields, namespaces, `ObsoleteState`), verify against the
  project's symbol packages, as the guide's Appendix B describes: the downloaded symbols are the
  only routine lookup. Microsoft Learn's Base Application or System Application reference is for
  the cases Appendix B names — symbols couldn't be downloaded, the object or member isn't in them,
  or a code pattern or event signature is needed — never a second check on what the symbols
  answered. Don't assert them from memory.