variables - SAS Character Values Exist in Numeric Type -

i have dataset @ work numeric variable when proc contents. however, when @ actual underlying data, there letters values part of variable 'r', 'a', etc....

was wondering if has explanation how/why sas allows kind of type assignment?

it's not except if :

1) have format applied variable displaying character variable. display appears character, underlying variable numeric.

proc format ;     value age      0 - 10='young'      11 - 12='preteen'      13 - 19='teen'     ; run;  proc print data=sashelp.class;     format age age.; run; 

2) if it's .r/.a, these special missing variables.

my guess have format applied data.