R devel - Dec 2016 - Proper attribution in Authors@R for the d3.js library by Mike Bostock

I have a couple of packages that use the d3.js library developed (and
copyrighted) by Mike Bostock.  One package uses it extensively, another only for
one function.  I use R to piece together parts files containing JavaScript that
I have written, which use d3.js functions and eventually the d3 library is
called from a temporary web page.

To date, I have pointed to Bostock's library in the Rd files.  However,
there are a growing number of packages that use d3.js now, and the habit
(standard?) now seems to be to put Bostock in Authors at R, but they do so in
different ways.  Here are a few examples:

D3partitionR:  Mike Bostock [aut, cph] (d3.js library in htmlwidgets/lib,
http://d3js.org. The partitionChart, sunburst, the treemap, the zoomable
circlePacking, the collapsible indented tree and the collapsible tree are all
derived from his works.)

scatterD3:  Mike Bostock [aut, cph] (d3.js library, http://d3js.org)

qrage:  Michael Bostock [ctb, cph] (D3.js library)

And there are others.

?person offers the following options that seem relevant:

"aut"
(Author) Use for full authors who have made substantial contributions to the
package and should show up in the package citation.

"com"
(Compiler) Use for persons who collected code (potentially in other languages)
but did not make further substantial contributions to the package.

"ctb"
(Contributor) Use for authors who have made smaller contributions (such as code
patches etc.) but should not show up in the package citation.

"cph"
(Copyright holder) Use for all copyright holders.

Questions: What is the proper attribution in this case?  Bostock is clearly cph.
Is that sufficient?  I'm not completely certain about the intentions of
"com" but it may fit.  "ctb" sounds insufficient and
"aut" seems to be a bit much (can you be an author of an R package and
not know about it?).  Is there a CRAN policy about this?

Thanks for any thoughts and guidance.  Bryan
****************
Prof. Bryan Hanson
Dept of Chemistry & Biochemistry
DePauw University
Greencastle IN 46135 USA
academic.depauw.edu/~hanson/index.html
github.com/bryanhanson