[R] dots in function names

[Robert W. Baer, Ph.D.]

In a (off-list) response to a question of frequency polygons, Dr Paul
Murrell writes:
> There's an "ann" arg which you can use to turn off the default labels
> (ann=FALSE).  Have you seen help(plot.default) as well as help(plot)?

Thank you again, Paul.  Interestingly, the ?plot help contains no mention of
the 'ann' parameter.  In fact, I have been guessing about what parameters
are legal in plot() or using examples from various R tutorials because ?plot
help just enumerates them with as ... after x and y.  I did not know that
plot.default existed although I now find it in response to a
help.search("plot").  This search produces many plot.something() functions.
I knew nothing about any of these "other" plot functions.

There has been mention of S3 objects on the list.  Is this relevant here?
Is 'plot.default' a method (or perhaps a type-dependent object
instantiation?) of the "plot function" object, or is 'plot.default' just a
second function object that shares a part of a name and uses a "convenience"
dot for readability?  Does R have standard naming conventions in this
regard?  I'm guessing that 'plot.default' is a method? of 'plot'.  Assuming
that other 'plot.something' functions are methods or instantiations of a
main 'plot' function object, how do I learn more about such a "main"
object's subparts short of studying code?  The ?plot help document does not
have a "see also" for plot.default or (many) other 'plot.something'
functions.  Is there a simple way to troll for such things when trying to
expand your horizons?

Any general hints on  how one should approach the self-education process in
this type of situation?

Thanks,
Rob Baer