The original ABA Activity Code Set released in 1997 includes 11 activity codes.
The ABA is in the process of revising its web site and has temporarily removed their UTBMS pages. Once their process is complete we will again supply a link to their content.
You can connect to a spreadsheet with the ABA Activity Codes reproduced by the LOC (with permission of the ABA) here: ABA UTBMS Activity Codes 1997