UML:

What is/are legal ways to show “information flow” between classes?

I saw an example of an EA UML composite diagram with classes dropped in and showing “information flows” between classes.

Btw, the line type (by default?) used by “information flow” is a dashed line with an arrow.

When I look at the book ‘UML Distilled’, I do not see even one example showing “information flow” between classes.

Summing up: Is the use of a composite diagram + classes and showing “information flows” between the classes a ‘strictly legal UML‘ way of showing flow between system elements? I.e., is it part of the defined UML 2.5.1 taxonomy?

Assuming “information flows” between classes is not valid UML, what is a valid UML way?

(1) For static diagrams (analogy in SysML is IBD diagrams)
(2) For dynamic diagrams (analogy in SysML is Activity diagrams)

Btw, my background: I learned some SysML, and now trying to learn UML.

Thanks
Avi