Hi, For your questions: 1)  It basically means if the first character of art_name is a 2, so it s not one we hold over the next rows, then retain that value. 2)  To concatenate different types, there is several options.  The main one would be put (and input) which convert data.  So string || put(number,best.)  will transform the number into a string defined by the format - best. in this case) - and then concatenate that string to the other. Glad you got your job done, you can wrap up the code lines as: data test;      set sample_wiki7;      retain artname2 artedit_id;      if substr(art_name,1,1) ne "2" then do;           artname2=art_name;      end;      version2 = put(version, 3.) ;      ID = catx('', artname2,version2) ; run; ... View more