Definition: This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
Input: Passage: Pub names are used to identify and differentiate each pub. Modern names are sometimes a marketing ploy or attempt to create "brand awareness", frequently using a comic theme thought to be memorable, Slug and Lettuce for a pub chain being an example. Interesting origins are not confined to old or traditional names, however. Names and their origins can be broken up into a relatively small number of categories. Question: What is the purpose of a pub name?
Output:
to identify and differentiate each pub