We published six platform pages covering how each assistant sources material when composing answers, and what can be done for each.
Why separate pages
Treating "the major AI platforms" as one thing hides the differences that matter: whether a given answer used live search, whether sources are attributed in the answer body, and how long the answer is. All three vary by platform and change across versions.
One content strategy, different placement
The pages describe differences, not a case for writing separate content per platform. A page with specifics, reachable by crawlers and corroborated elsewhere performs better everywhere. What the differences change is where to place material.
What cannot be done
Each page states plainly what is not achievable on that platform — ordering within an answer cannot be controlled, and no single question can be guaranteed to name you.