Mwe-upwiz-desc

What is the context of Mwe-upwiz-desc ("Description")? What follows it?

Apparently this is followed by a language name (or language selector)

Oh dear. I guess there might be some languages which are going to struggle to fit a translation of this message with the language selector. Anyway, have documented.

Best report this issue in bugzilla:.

Bug report done on bugzilla:26231

Thanks Lloffiwr, I have commented on bugzilla.