Only showing icons on posts, not pages

Edited to add –
I added the respective class to the document links on a page, using the ‘Additional’ field, and this works when just viewing a page, but now the list of pages created as search returns shows 2 document icons!

So the CSS class is attributed automatically content in posts, but not pages, unless those pages area then listed in response to a search query. If I manually attribute the class to a document link on a page, it works when just viewing the page but then, when seeing the returned listed pages in response to a search query, the icon then appears twice – once because I’ve manually added it, and twice because it’s automatically assigned it when returning that page as a search query.