This feature makes CafeTran transfer the surrounding tags of the source matches in the current source segment to the target language segment. It functions when the user transfers a target fragment/term, auto-assembling, a fuzzy match or machine translation containing the matched fragments. It is also active during the automatic insertion of the best translation result into the target segment editor.
The feature is on by default. You can deactivate it via Edit > Preferences > Auto-assembling tab > Transfer tags to matches option.