STLS

STLS is an initialism with multiple meanings across different domains, and there is no single universally accepted definition. Its interpretation is highly context-dependent and can vary by field or even by organization.

In information technology and communications, STLS is sometimes used as an informal shorthand for StartTLS, the mechanism that upgrades an existing plaintext connection to a TLS-encrypted channel in protocols such as SMTP, IMAP, POP3, and LDAP. The official standard term is STARTTLS, but STLS can appear in some vendor documentation or informal discussions as a shorthand.

In numerical analysis and statistics, STLS can denote Structured Total Least Squares, a variant of the Total Least Squares method that accounts for known structure in the measurement or model errors. Relatedly, Sparse Total Least Squares is a related approach that combines total least squares concepts with sparsity constraints to identify a small set of influential parameters.

Beyond these uses, STLS may appear as an acronym for various organizational names, project titles, or product designations in different contexts. Because acronyms are frequently reused, STLS should be interpreted from its surrounding text to determine the intended meaning. See also TLS, STARTTLS, and related security and numerical methods terms for broader context.