LSP dictionaries may have communicative functions, such as helping users to understand, translate and produce texts.
Dictionaries may also have cognitive functions such as helping users to develop knowledge in general or about a specific topic, such as the birthday of a famous person and the inflectional paradigm of a specific verb.
An LSP dictionary that attempts to cover as much of the vocabulary in a subject field as possible is classified by Nielsen as a maximizing dictionary, and one that attempts to cover a limited number of terms within a subject field is a minimizing dictionary.
A common form of LSP dictionary is a usage dictionary for a particular field or genre, such as journalism, providing advice on words and phrases to prefer, and distinctions between easily confused usages.
Many such works also have elements of a style guide, though most of the latter are not in dictionary format, but arranged as a series of rules in sections, and more concerned with grammar and punctuation.