I remember doing some Internet searches for this over a decade ago, back when I started doing my own laundry :). Maybe I didn't look thoroughly enough - but between that search and the actual labels on the clothes I had, I saw no indication of a standard.

Might be because my clothes were probably a mix of branded things sold on EU market, and (mostly) unbranded ones I bought on a bazaar, which could've been imported from Turkey or East Asia.