hreflang="cu"

cu is a valid hreflang value for Church Slavic.

Language: Church Slavic (cu, ISO 639-1)

Example

<link rel="alternate" hreflang="cu" href="https://example.com/cu/" />

The code is case-insensitive for Google. The conventional spelling is a lowercase language, a title-case script and an uppercase region: cu.

Without a region, the annotation targets every Church Slavic speaker regardless of country. Regional versions sit next to the language-only version in one cluster.