When a character's wrists cross directly over each other.
It can be seen sometimes with X Arms - a Japanese gesture where a character signs 'x' with their wrists by overlapping them, and having them angled in a slanted manner to form an X.
Characters may also do it to shield themselves, as a form of self defense.
The gesture may also be found in some Mudras (gestures from Hinduism and Buddhism).
Can sometimes be seen during Shibari as a particularly restrictive form of Box Tie, as a middle ground before a Reverse Prayer.