---
title: "Cross-file integrity"
summary: >-
  Built-in rules flag broken links and missing anchors, enforce
  per-file section schemas, and keep Markdown in the right folders.
  Schemas can be inline on a file kind or shared via `proto.md` files.
icon: link
link: "/guides/directives/enforcing-structure/"
rules: ["MDS027", "MDS020", "MDS033", "MDS069"]
weight: 8
group: "A connected docs tree"
---
# Cross-file integrity

A linter that only sees one file at a time cannot catch a link
that points at a heading another file just renamed. mdsmith
resolves links and anchors across the whole workspace.

`MDS027` flags broken links and missing anchors. `MDS020`
enforces a per-file section schema: required headings,
front-matter fields, and ordering. `MDS033` keeps each Markdown
file in an allowed folder. `MDS069` keeps a front-matter field
unique across a set of files — document ids, slugs, or titles
that no two files may share. The
[rule directory](/rules/)
has the full reference for each.

A schema can be declared inline on a [file
kind](../guides/file-kinds.md) or shared across files via a
`proto.md` template, so a whole directory validates against one
source of truth.