Writing credits for Roberta (1935)

I tried (250901-082001-279000) to correct the writing credits for Roberta (1935), which list Jerome Kern even though he is only credited as writing the music for the original stage version (Otto Harbach is then credited for writing the musical book and lyrics), but the Kern deletion was rejected and the other ordering revisions are pending. I can't understand this; those responsible only for composing music don't belong in the writing credits. Frederick Loewe isn't listed in the writing credits for My Fair Lady, nor is Leonard Bernstein for the versions of West Side Story.