IEC TS 61994-4-4:20 18可作为IEC TS 61994-4-4:20 18 RLV获得，其中包含国际标准及其红线版本，显示了与上一版本相比技术内容的所有变化。IEC 61994-4-4:20 18给出了代表现有技术水平的声表面波（SAW）器件单晶晶片的术语和定义。与上一版相比，此版本包括以下重大技术变更: -已考虑IEC 62276:2016中给出的新术语和定义； -总标题已根据2009年TC 49标题的变化进行了更改。 -零件标题已根据IEC 62276:2016的标题进行了更改。

IEC TS 61994-4-4:2018 is available as IEC TS 61994-4-4:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 61994-4-4:2018 gives the terms and definition for single crystal wafers for surface acoustic wave (SAW) devices representing the state of the art. This edition includes the following significant technical changes with respect to the previous edition:
- the new terms and definitions given in IEC 62276:2016 have been taken into account;
- the general title has been changed according to the change in the title of TC 49 in 2009.
- the part title has been changed according to the title of IEC 62276:2016.