read  | 
prompt  | Force the dialog to appear from within a program.  | 
t=dat, txt   | ASCII (plain text) files.  | 
t=wk1, wk3  | Lotus spreadsheet files.  | 
t=xls  | Excel spreadsheet files.  | 
t  | Read data organized by series. Default is to read by observation with series in columns.  | 
na=text  | Specify text for NAs. Default is “NA”.   | 
d=t  | Treat tab as delimiter (note: you may specify multiple delimiter options). The default is “d=c” only.  | 
d=c  | Treat comma as delimiter.  | 
d=s  | Treat space as delimiter.  | 
d=a  | Treat alpha numeric characters as delimiter.  | 
custom = symbol  | Specify symbol/character to treat as delimiter.  | 
mult  | Treat multiple delimiters as one.  | 
names  | Series names provided in file.  | 
label=integer  | Number of lines between the header line and the data. Must be used with the “name” option.  | 
rect (default) / norect   | [Treat / Do not treat] file layout as rectangular.  | 
skipcol = integer  | Number of columns to skip. Must be used with the “rect” option.  | 
skiprow = integer  | Number of rows to skip. Must be used with the “rect” option.  | 
comment= symbol  | Specify character/symbol to treat as comment sign. Everything to the right of the comment sign is ignored. Must be used with the “rect” option.  | 
singlequote  | Strings are in single quotes, not double quotes.  | 
dropstrings  | Do not treat strings as NA; simply drop them.  | 
negparen  | Treat numbers in parentheses as negative numbers.  | 
allowcomma  | Allow commas in numbers (note that using commas as a delimiter takes precedence over this option).  | 
currency= symbol  | Specify symbol/character for currency data.  | 
t  | Read data organized by series. Default is to read by observation with series in columns.  | 
letter_number (default=“b2”)  | Coordinate of the upper-left cell containing data.  | 
s=sheet_name  | Sheet name for Excel 5–8 Workbooks.   | 
bycross (default) / byper   | Structure of stacked pool data [cross-section / date or period] (only for pool read).   |