ETSI published all updated TTCN-3 specification parts and extensions (2018 edition), you may access the actual documents via http://www.ttcn-3.org/index.php/downloads/standards or using the updated TTCN-3 Quick reference card from http://www.blukaktus.com.
For TTCN-3 users the updated core language provides a couple of improvements, e.g. mixed list/assignment notation, variables of timer/port types, declarations at any place where statements are allowed, renaming (local scope only) of imported module. The terms ‘object’ and ‘object reference’ have been introduced to cover component, default, port and timer types. Users may have a look to section 15.11 regarding the concatenation of templates of string/list types. Tool provider may find additional updates in the ETSI document MTS(18)073007r1 (all changes are marked!) or via mantis (http://oldforge.etsi.org/mantis/view_all_bug_page.php). You may expect more news coming soon with the new Object-oriented features (ES 203 790).