Cornell Ecology Programs (CEP) used eight-letter
abbreviations for species and site names. In species, the names were
formed by taking four first letters of the generic name and four
first letters of the specific or subspecific epithet. The current
function first makes valid R names using make.names
,
and then splits these into elements. The CEP name is made by taking
the four first letters of the first element, and four first letters
of the last (default) or the second element (with
seconditem = TRUE
). If there was only one name element, it is
abbreviate
d to eight letters. Finally, the names are
made unique which may add numbers to duplicated names.
The CEP names were originally used, because old FORTRAN IV
did not have CHARACTER
data type, but text had to be stored
in numerical variables, which in popular computers could hold four
characters. In modern times, there is no reason for this limitation,
but ecologists are used to these names, and they may be practical to
avoid congestion in ordination plots.