Facebook page admins have lost the ability to mark comments on their pages as spam, as they now only have options to remove is entirely and deal with the user from there.
Now, when admins remove a comment, they are given three options: Undo the removal, report the comment as abuse, or ban the user who posted the comment.
AllFacebook first reported the change to pages, making the point that this significantly changes how unwanted comments are dealt with. Now, users will always know that their comments were deleted. When admins could simply mark comments as spam, they still appeared to the poster as well as the poster's friends.
From the Facebook help center:
What happens when a Page admin marks a post as spam?
The post is removed from the Page and isn't visible to anyone except the person who posted it and the poster's friends. Admins of the Page can also view the post by clicking on the Spam filter in the Page's activity log.
Page admins still have the option to mark Timeline posts as spam, however. Once marked as spam, the posts will become invisible to most users and can only then be viewed in the Activity log.