The style library should always be up to date. If a DIN EN ISO or other Standard is changing the changes should be available in a CAD Software.
In Version 2017 an importand weld symbol is missing. Please add this to Inventor 2017 and also to AutoCAD Mechanical and other ADSK applications.
![welding.png welding.png](https://forums.autodesk.com/t5/image/serverpage/image-id/298977iAC419C7AAA783B93/image-size/large?v=v2&px=999)