Within limits, these are particularly important given that it is unlikely that they were produced FOR the ethnographer, and thus directly represent what the people say to each other.
Below are two pages from the New York City guide to its high schools as it is given to students and parents.
Ethnographically, this is both a source of information about the high schools, and a source of information about the public rhetoric of the Board of Education (note for example, that the word "academic" is used only in the paragraph about "alternative high school" and in the context of 'support'. The high schools generally considered academic are described as "competitive" within a legal context.)
Obviously, the last statements are the beginning of an analysis of the document.