When the latest version of a full pattern file is available for download from the Trend Micro ActiveUpdate server, 14 "incremental patterns" also become available. Incremental patterns are smaller versions of the full pattern file that account for the difference between the latest and previous full pattern file versions. For example, if the latest version is 175, incremental pattern v_173.175 contains signatures in version 175 not found in version 173 (version 173 is the previous full pattern version since pattern numbers are released in increments of 2. Incremental pattern v_171.175 contains signatures in version 175 not found in version 171.

To reduce network traffic generated when downloading the latest pattern, OfficeScan performs component duplication, a component update method where the OfficeScan server or Update Agent downloads only incremental patterns. See Update Agent Component Duplication for information on how Update Agents perform component duplication.

Component duplication applies to the following components: