There are a few people who try to save lines of code add multiple codes to the hreflang= syntax.
I saw this craziness for the first time this week. The site owner told me the SEO who implemented it was told by Google they can cut down on the number of XML sitemap entries by added multiple country and language codes to the syntax.
<xhtml:link rel=”alternate” hreflang=”es-ES;fr;fr-BE;fr-CH;pt;it;it-CH;de-CH;de-AT;de;en-GB;en;en-IE”
Clarification: No this does not work. Google is very clear that you must create a separate URL element for each URL.