paste.Rd
%c% is just a short operator implementation for paste(x, y, separator="").
x %c% y
returns the concatenation as string.
R-Core does not consider it a good idea to use + as an operator not being commutative. So we use c here.
See the discussion:
https://stat.ethz.ch/pipermail/r-devel/2006-August/039013.html
and https://stackoverflow.com/questions/1319698/why-doesnt-operate-on-characters-in-r?lq=1
Still the paste syntax seems sometimes clumsy in daily life and so %c% might spare some keys.
"foo" %c% "bar"
#> [1] "foobar"
# works with numerics as well
345 %c% 457
#> [1] "345457"