Diphthongverschiebungen

It looks like the topic name is truncated: "Diphthongversc...". Could you please provide the full term or clarify the intended subject? For example, are you referring to diphthongs (vowel sounds formed by articulating two adjacent vowel qualities), a specific linguistic concept like diphthongization, or a coined term such as "diphthongverse"? Once you confirm, I’ll write a concise, neutral wiki-style article under 300 words. If you’d like, I can also start with a general article on diphthongs in the meantime.