IEC 61837-2:2018 deals with standard outlines and terminal lead connections as they apply to surface-mounted devices (SMD) for frequency control and selection in ceramic enclosures, and is based on IEC 61240:2016. This edition includes the following significant technical changes with respect to the previous edition: a. revision of the figures to match the notation of the drawings of IEC 61240:2016; b. addition of 7 enclosures as follows: DCC-6/5032A, DCC-6/3225A, DCC-4/3215C, DCC-6/2016A, DCC-2/2012C, DCC-2/1610C, DCC-4/1210C. As a result, this third edition contains a total of 45 enclosure types, which are listed in Table 1.