: Could stand for "Spanish" or another language, but without more context, it's hard to determine. Often, such abbreviations refer to subtitles or audio tracks.
: This refers to the file format and container. MKV stands for Matroska, a flexible, open-standard video container format that can hold an unlimited number of audio, video, and subtitle tracks. 8951-Wasabi -2001- 720p D S spa eng v.mkv
.mkv (Matroska Multimedia Container), a common high-quality video format. : Could stand for "Spanish" or another language,