\documentclass{article}

\usepackage[biborder]{oonumbib}

\NEW{Book}{\cRainbow}{
  \s\MYauthors{\name{Bob Jones}%--figure out how to ignore this space???
               \name{Robert Frost}}
  \s\MYtitle  {Life}
  \s\MYyear   {2002}
  \s\MYpublisher{Addison-Welsey}
  \s\MYcity   {New York}
  }

\NEW{Book}{\cNull}{
  \s\MYauthors{\name{Rob Wash}}
  \s\MYtitle  {Not Cited, so not in the Bibliography}
  }

\NEW{Article}{\cFish}{
  \s\MYauthors{\name{Fish Abbot}}
  \s\MYtitle  {Not Fishy}
  \s\MYjournal{Stupidity Weekly}
  }

\NEW{Article}{\cPutting}{
  \s\MYauthors{\name{{the Society for Putting Things on Top of Other Things}}}
  \s\MYtitle  {Things}
  \s\MYjournal{Python Weekly}
  }

\NEW{Name}{\nName}{
  \s\MYname{Rufus Wainwright}
  }

\begin{document}

\noindent
\forfirstmostlastonenone{Source}{1}{2}{3}{4}{\emph{5}}{} = 5\\
\forfirstmostlastonenone{Source}{1}{2}{3}{\emph{4}}{5}{\cRainbow{}} = 4\\
\forfirstmostlastonenone{Source}{1}{2}{\emph{3}}{4}{5}{\cRainbow{}\cNull{}} = 13\\
\forfirstmostlastonenone{Source}{\emph{1}}{\emph{2}}{3}{4}{5}{\cRainbow{}\cNull{}\cFish{}} = 123

\forfirstmostlastonenone{Source}{1\MYtitle}{2\MYtitle}{3\MYtitle}{4\MYtitle}{5\MYtitle}{\cRainbow{}\cNull{}\cFish{}}

\forfirstmostlastonenone{Source}{1\MYtitle}{2\MYtitle}{3\MYtitle}{4\MYtitle}{5\MYttile}{\cRainbow{}}

\forfirstmostlastonenone{Book}{\relax\MYtitle}{2\MYtitle}{3\MYtitle}{4\MYtitle}{5\MYttile}{\cRainbow{}}
\forfirstmostlastonenone{Book}{\MYtitle}{2\MYtitle}{3\MYtitle}{4\MYtitle}{5\MYttile}{\cRainbow{}}

z\forfirstmostone{Name}{\parselast\ et.\ al.}{}{\parselast}{\nName{}}\\
z\forfirstmostone{Name}{\parselast\ et.\ al.}{}{\parselast}{\name{Rob Jones}}\\
z\forfirstmostone{Name}{\parselast\ et.\ al.}{}{\parselast}{\name{Rob Jones}\name{Joanie Miller}}

z\nName{\parselast}\\
\makeatletter
z\@firstetal{\nName{}}\\
z\@firstetal{\name{Rob Jones}\name{Joanie Miller}}\\
z\@firstetal{\cRainbow{\MYauthors{}}}\\
\makeatother
z\cPutting{\citet{}}

\cRainbow{\citet[pg.\ 42]} wrote a book.~\cFish{}\\
\cRainbow{\citet} wrote a book.~\cFish{\citep[pg. 42]}\\

\name{Bob Jones}\\
\ifnotempty{Fish}{Fish isn't empty.}\\
\ifnotempty{\name{Bob Jones}}{BJ isn't empty.}\\
\ifnotempty{}{This should't print.}
\cRainbow{\MYauthors}

\cPutting{\Citet{} is used at the start of a sentence.~\Citep[pg. 42]}

\makeatletter
\def\foo{\@Listnamesinvertfirst{\MYauthors}}
\cRainbow{\foo}

\@capitalize{fish}
\makeatother

\bibliography{}

\end{document}