Every SYN corpus contains all the synchronic written corpora of the SYN series published up until the time of the given version's publication. The corpus SYN version 9 therefore contains the corpora SYN2000, SYN2005, SYN2006PUB, SYN2009PUB, SYN2010,SYN2013PUB, SYN2015 and SYN2020; additionally, it contains a journalistic component predominantly from the years 2010–2019 (already included into SYN version 4, SYN version 5, SYN version 6, SYN version 7 and SYN version 8) and as yet unpublished journalistic texts from 2019 in yearly volume almost 150 mil. words.

The SYN corpus is not representative; the dominant component is journalism, which is the result of the predominance of journalistic corpora SYN2006PUB, SYN2009PUB, SYN2013PUB and the journalistic component from the years 2010–2019.

Continuous annual updates of journalistic texts in the SYN-series corpora also had a side effect: many issues of newspapers and magazines that had previously been included into some of the SYN-series corpora (versions 5 to 8) had to be re-used also in SYN2020. As a consequence of this non-empty intersection of SYN2020 with older SYN-series corpora, SYN version 9 cannot be a disjunctive unification of all its components. However, all the journalistic texts included into both SYN2020 and some other SYN-series corpora are included only once in SYN version 9.

The SYN version 9 corpus is referential, and will remain accessible to users even after newer versions have been published. It is however necessary to keep in mind that the linguistic information will become outdated, as a natural result of the referential nature of the corpus. Individual versions of the corpus SYN will continue to be published regularly every year with the addition of current journalistic data, and every new addition will be given the attribute value <doc syn> equal to the version of the SYN corpus in which the given text first appeared; for example a subcorpus corresponding to the above mentioned (as yet unpublished) journalistic component can be created from the SYN version 9 with the help of the condition syn="v9"¹⁾.

The composition of the journalistic part of the corpus SYN version 9 covers the production of most of the national daily newspapers (Mladá fronta DNES, Lidové noviny, Právo, Hospodářské noviny, Blesk, Sport), regional daily newspapers (chiefly Deníky Bohemia and Moravia published by Vltava Labe Media) and non-specialized magazines (Reflex, Respekt, Týden) from the years 1998–2019; the total number of journalistic titles is almost 200. The following graphs show the composition of the SYN corpus based on the main text types over the years and offer a closer look at the composition of the journalistic section.

Composition of the corpus SYN version 9

Composition of the journalistic part of the corpus SYN version 9

Generally speaking, structure and annotation of SYN version 9 are based on that of the SYN2020 corpus. In particular, hierarchy of structural tags for SYN version 9 has been taken over from SYN2020, as well as the lemmatization and morphological tagging. Please note that SYN version 9 differs in this from its predecessor, SYN version 8.

This correspondence of structure and annotation between SYN version 9 and SYN2020 only has the following exceptions:

• introducing the additional attribute <doc syn> for the creation of subcorpora corresponding to the original reference corpora;
• replacing syntactic annotation in the SYN2020 corpus with a pilot version of phraseme annotation.

— Michal Křen