[Dev-luatex] Hyphenation/lccode

Before I ask my second question, I ask a third: I load German hyphenation patterns and want to hyphenate a word. Before that I use for i in string.utfvalues("äÄöÖüÜß") do tex.lccode[i] = i end and then I hyphenate for example "Krönung", which gets (if I understand TeX) translated to lowercase characters (with lccode) and then gets hyphenated. Works fine. Now I want to hyphenate the word "KRÖNUNG" (the same word, only all upper case letters), and I wonder why that works. The lowercase equivalent would be "krÖnung" (according to the lccode setting above), and I wonder why this gets hyphenated. Just luck? Good weather? Patrick