Data issues

Hi,
I was wondering if I need data on all declared variables for estimation. While perusing some .mod files I noticed that data files contain data on one or two variables only.
Also is there a way to read data without using the estimation command?
Regards,
Adeem
I was wondering if I need data on all declared variables for estimation. While perusing some .mod files I noticed that data files contain data on one or two variables only.
Also is there a way to read data without using the estimation command?
Regards,
Adeem