CSL 1.0.1 specification. CSL 1.0.1 schema.
The CSL 1.0 specification provides the most detailed and precise description of CSL 1.0. The CSL 1.0 primer offers a less technical introduction to CSL 1.0, and discusses how small style edits can be made. Information on validating, sharing and requesting CSL styles can be found at https://github.com/citation-style-language/styles/wiki.
An additional resource is the CSL 1.0 schema, written in the RELAX NG compact syntax. It describes the XML structure of CSL styles and locale files, and can be used for validation.
Zotero users can find additonal information in the Zotero wiki.
CSL 0.8.1 schema. The Zotero wiki contains an entry on the CSL 0.8.1 syntax. A tutorial for editing CSL 0.8.1 styles can be found at http://www.condast.com/zotero/index.html.
CSL 0.8 schema.