This will help in locating the actual "paper" or the standard it refers to.
: It is common for large-scale infrastructure or software projects to use these identifiers for versioned technical manuals or requirements papers. SS-Nts-020_v.7z.001
: This may be an internal organizational code, a niche technical specification (often seen in aerospace, telecommunications, or defense), or a specific version of a System Specification (SS) . This will help in locating the actual "paper"