git:20260512.df85811 to git:20260729.3b91eed

5 added, 1 removed. Audit A to A.

---

name: seo-hreflang

- description: Use when auditing or generating hreflang for i18n SEO. Covers HTML link tags, HTTP headers, XML sitemap hreflang, self-referencing, return tags, x-default, ISO 639-1 + ISO 3166-1 code validation.

+ description: Use when auditing or generating hreflang tags for i18n/multilingual SEO.

user-invocable: false

related-skills: seo, seo-technical, seo-sitemap

---

+ <objective>

+ Audits or generates hreflang across all three implementation surfaces — HTML `<link>` tags, HTTP headers, and XML sitemap `<xhtml:link>` entries — validating self-referencing, return tags, x-default, and ISO 639-1 + ISO 3166-1 code correctness via `scripts/parse-hreflang.ts`. Lists the common mistakes: missing self-reference, missing return tags, invalid region codes (`en-UK` vs `en-GB`), HTTP/HTTPS mismatch between alternates, and trailing-slash inconsistency.

+ </objective>

# Hreflang / i18n SEO

## Workflow

1. Detect hreflang tags (HTML `<link>`, HTTP header, or XML sitemap)

2. Run `scripts/parse-hreflang.ts` → validate

3. Check self-referencing, return tags, x-default

4. Verify language/region codes (ISO 639-1 + ISO 3166-1)

## Common Mistakes

- ❌ Missing self-reference (`<link rel="alternate" hreflang="fr" href="/fr/">` from `/fr/`)

- ❌ Missing return tags (A → B but not B → A)

- ❌ Invalid codes (`en-UK` instead of `en-GB`)

- ❌ HTTP/HTTPS mismatch between alternates

- ❌ Mixing trailing slashes

## Implementation Options

1. **HTML head**: `<link rel="alternate" hreflang="fr-FR" href="https://example.com/fr/">`

2. **HTTP Header**: `Link: <https://example.com/fr/>; rel="alternate"; hreflang="fr-FR"`

3. **XML Sitemap**: `<xhtml:link rel="alternate" hreflang="fr-FR" href="https://example.com/fr/"/>`

## x-default

Required for international landing/locale selector pages:

```html

```