| In force components | 
| Number 
 | Title | Status | 
| K.77 (07/19) 
 | Characteristics of metal oxide varistors for the protection of telecommunication installations | In force 
 | 
| 
 | 
| Superseded and Withdrawn components | 
| Number 
 | Title | Status | 
| K.77 (01/09) 
 | Characteristics of metal oxide varistors for the protection of telecommunication installations | Superseded 
 | 
| K.77 (2009) Corrigendum 1 (05/11) 
 |  | Superseded 
 | 
| K.77 (2009) Amendment 1 (12/13) 
 | New Appendix III: Characterizing thermally protected MOVs using a.c. step stress testing | Superseded 
 |