ETSI published the TTCN-3 updated standards (2017 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 http://www.blukaktus.com/TTCN3QRC_viewme.pdf.
The following provides a short list of innovations regarding the version 4.9.1 of the core language in ETSI ES 201 873-1:
- an optional default type for user-defined union data types (chapter 6.2.5),
- a new “=>” operator applicable on string type to access decoded data (chapter 7.3),
- external functions that may return data of a template type (chapter 16.1.3),
- the possibility to retrieve attribute values from types or template instances (chapter 27.8),
- the port operation “.setencode” for the dynamic selection of encoding attributes (chapter 27.9),
- an extended parameterization of encode/decode functions for the dynamic selection of encoding attributes (chapter C.5.1 – C.5.4),
- new predefined functions for encoding/decoding of octetstrings (chapter C.5.5 and C.5.6).