When you actually read what's written in the Help Center, it strongly implies that only answers need to give attribution (see added emphasis):
Plagiarism - posting the work of others with no indication that it is not your own - is frowned on by our community, and may result in your answer being down-voted or deleted.
When you find a useful resource that can help answer a question (from another site or in an answer on Stack Overflow) make sure you do all of the following
Can this be changed to be more inclusive of questions (and perhaps tag wikis)?
My best suggestion:
Plagiarism - posting the work of others with no indication that it is not your own - is frowned on by our community, and may result in your post being down-voted or deleted.
When you use a resource in your post (e.g. from another site or in an answer on Stack Overflow) make sure you do all of the following