[NTG-context] Using \pdfnames and friends.

Hello, I'm trying to use \pdfnames with MkIV, but I can see from the sources that it's a no-op and should be replaced with \pdfbackendsetname. So I use \pdfbackendsetname{EmbeddedFiles}{22 0 R}, trying to achieve the same thing as \pdfnames{/EmbeddedFiles 22 0 R}, but "22 0 R" is surrounded by parentheses, as if it were a PDF string, so that I end up with the useless "/EmbeddedFiles (22 0 R)". Similarly, \pdfbackendsetcatalog{PageMode}{/UseOutlines} produces "/PageMode (/UseOutlines)". What am I doing wrong? Best, Paul