ACTLINE is an identifying number for each activity record. Activity records can be uniquely identified using CASEIDA and ACTLINE.

ACTLINE is also used with ACTLINEW to link who records to activity records.

ACTLINE is available only if you select a hierarchical extract. If you request a hierarchical extract and plan to construct time use variables in your statistics package, this variable may be useful to you. If you request a rectangular extract and plan to construct time use variables through the extract system, ACTLINE will not be included in your extract, as persons are the unit of observation for rectangular extracts rather than activity or who records.

2003-2010: All activities.