SynTag is a so called tree bank, containing syntactically annotated text from 158 articles from the corpus Press-65, with about 100 000 running words. The annotation contains the relations of constituents and words, such as subjects or other arguments of finite verbs, in up to 12 levels of analysis. Additionally, there are simple word tags. The data still contains some errors, which will be corrected in the future.
More information (in Swedish) about SynTag can be found in this manual.