The documentation for the @Author function states that “If there are multiple Authors fields, returns the contents of the first Authors field found in the document.”
This is literally the case in R5, ie if a document contains two Authors fields (eg Authors1 and Authors2, in that order) then the function will invariably return the contents of the first one. However, if the first Authors field is blank then R5 will of course return blank but in 6/7 the @Author function will ignore the blank field and return the value of the first non-blank Authors field.
I was caught out by this just recently.
Hope somebody finds this useful.
Mark