Deprecate maction?

Dear WWW-Math mailing-list,

Within the W3C-Math-Working-Group, we have as charter to revise what was 
proposed in MathML3 to make it current and sharper-readable. Among the 
elements who appear to be candidate for a deprecation process are the 
`maction` element.

The MathML3 (current) spec 
[says](https://www.w3.org/TR/MathML/chapter3.html#presm.maction) that 
`maction` can be used to mark a sub-expression so that interactions of 
particular types can happen: toggle (switch between alternatives), 
statusline (show in the status-line) and tooltip (show a tooltip on 
top), and input (show a textfield).

It appeared to us that neither statusline nor tooltip are current and 
that toggle is likely of little use. Is maybe input too?
All of this can be performed in a more browser- and user-relevant 
fashion using javascript listeners, albeit in a less declarative 
fashion.

I would like, thus, to suggest to enter `maction` into a deprecation 
process: it would make this element valid (but deprecated) in MathML 4 
and it would be removed in MathML 5.

What do people on this list think of this proposal?
If you have other uses of `maction`, is this going to be a problem and 
can you describe the use that you make?

Thanks in advance for your answers.

Paul

PS: implementations I know of include Safari and Firefox: they can be 
checked in the MathML3 test-suite: 
[highlight](https://www.w3.org/Math/testsuite/build/main/Presentation/DynamicExpressions/maction/mactionBhigh1-full.xhtml), 
[statusline](https://www.w3.org/Math/testsuite/build/main/Presentation/DynamicExpressions/maction/mactionBstatus1-full.xhtml), 
[toggle](https://www.w3.org/Math/testsuite/build/main/Presentation/DynamicExpressions/maction/mactionBtoggle1-full.xhtml), 
[tooltip](https://www.w3.org/Math/testsuite/build/main/Presentation/DynamicExpressions/maction/mactionBtooltip1-full.xhtml).