This line is intended to increase the readability for a human user and should be viewed as a helpful comment line. It should never be used for reading the file programatically.
Please align the short headers with the values in the data columns right below.
Because blank is used as separator between the titles, each title must be one word (no blanks allowed).
starttime endtime <title_for_each_variable> ...
starttime endtime mm numflag_mm mm_off numflag_mm_off Na+ numflag_Na+ Ca++ numflag_Ca++ NH4+ numflag_NH4+ K+ numflag_K+ NO3- numflag_NO3- Mg++ numflag_Mg++ SO4-- numflag_SO4-- Cl- numflag_Cl- pH numflag_pH cond numflag_cond