The first lines of an RDB file are usually comment lines (they begin with a '#' sign). After the comment lines there is a line of variable names (the name of each field column), and followed by a line that describes the length of each variable and the data type. The actual data lines begin next. All fields are separated by TAB characters.
Here is an example RDB file
# Rdb # Trace Element Data For Urban Land Use (Springs) # [<, less than; E, estimated] # P01000= Arsenic Dissolved (ug/L as As) # P01005= Barium Dissolved (ug/L as Ba) staid date time r01000 p01000 r010005 p01005 15s 8s 4s 1s 9n 1s 9n 02331247 19930614 1530 E 14.4 10.9 02331250 19930614 1600 < .01 < .01Note: s, string variable; n, numeric variable; r, remark code; p, constituent code