The notion of context (see Section 2.1, "Context") is not defined exactly, thus deciding on the tfa value and subsequently evaluating the communicative dynamism can be quite difficult, above all in certain marginal cases. This section contains further guidelines that can be helpful in determining the contextual boundness. They include strong tendencies exhibited by Czech and the influence of four important factors:
lexical content of an expression (see Section 4.1, "Topic-focus articulation and the lexical content of an expression"),
semantic type of the dependency relation (see Section 4.2, "Topic-focus articulation and the semantic type of dependency relation (functor)"),
relationships between clauses (see Section 4.3, "Topic-focus articulation and relationships between clauses"),
sentential modality (see Section 4.4, "Topic-focus articulation of questions").
All instructions described in this section are auxiliary instructions, the main criterion for assigning the tfa value is always the relationship of a node to its context.