What I am trying to do, is use a wildcard for character variables (in this case, ICD-9 codes) within proc format.    To keep things simple (because a lot of ICD coding has a lot of suffixes and we only care for the primary prefix), I am using coding for uncomplicated hypertension (ICD-9 code 401), which has 2 subcodes (4011, 4019).  I do not want to add a format definition for 4011 and 4019 (this becomes much more arduous when dealing with many other ICD-9 codes). I simply want to create a format by the prefix, and everything after the prefix will be assigned the same format definition.    The prefix code I am interested in, in this case, is 401 (as a character).   I have tried using a colon "401:" = "Hypertension Uncomplicated - ICD-9" in proc format (in an attempt to include 4011 and 4019), to no avail.   Here is my code:     proc format; value $test "401" = "Hypertension Uncomplicated - ICD-9" ; run; quit; data test_form; input PatID ICD9$; datalines; 1 401 2 4011 3 4019 ; data test_form; set test_form; format ICD9 $test.; run; proc print data = test_form NOOBS; title "Testing format wildcards"; run; title;   As for outputs:  Current Output: PatID ICD9 1 Hypertension Uncomplicated - ICD-9 2 4011 3 4019     Desired Output: PatID ICD9 1 Hypertension Uncomplicated - ICD-9 2 Hypertension Uncomplicated - ICD-9 3 Hypertension Uncomplicated - ICD-9     ... View more