Short answer
Islamic law does not treat every sexual position as prohibited. The important distinction is whether the act itself falls within the permitted form of marital intimacy and avoids prohibited conduct.
Islamic Guidance
What Islam teaches
The Qur'an permits spouses intimacy with one another while the surrounding verses and prophetic guidance establish boundaries. Classical scholars distinguish between permissible variations and prohibited forms of intercourse.
Practical Guidance
What you can consider
Couples should learn the underlying principles rather than relying on internet lists. When in doubt about a specific practice, ask a qualified Islamic scholar privately.
Sources
Qur'an 2:223; Qur'an 2:222.