It is now possible (but not easy) for anyone who is determined enough to create a xanadoc, and send it to others, who may open and use it.  (Note that the World Wide Web was available for several years before the Mosaic editor made it easy for the public.)

But there ARE invincibility frames. 0.5 seconds.

I have checked the following close stackoverflow sources : Relation passed to #or must be structurally compatible. Incompatible values: [:references]