1. In either the basic or advanced editor, in the 100 tag subfield a, type You & I 2. In the basic editor click the "Tag editor" icon, or in the advanced editor type ctrl+shift+L to look up an authority record 3. Examine the prefilled search term in the popup window Expected result: You & I Actual result: You
I think there is an older bug for this one - will try to locate it later.
Ah, tricksy summary, I thought that bug was about the actual search, not about what's prefilled in the search form, and was specific to corporate names, not all authority-controlled fields. *** This bug has been marked as a duplicate of bug 11446 ***
Ah, you beat me to it - the other bug could probably be improved too, but I believe the underlying problem is probably the same.