Discussion on the use of altimg attribute in <math>

[samimaattaCelia]

Altimg attibute for <math> is not in MathML Core and it is in MathML 3, MathML 4.

What we know now

The experience is shared that reading systems that don't support MathML code, display the fallback image.

Edit: Removing this part, because it's about alttext:
Some contents I have seen in the alttext: ASCIIMath, LaTeX or "math as it is spoken".

It is used at Tibi for ASCIIMath fallback.
Remove end.

Edit: Addition about challenges:

Challenges

If the fallback image has errors in it, it will be difficult for us to fix it in post production. It would always have to be sent back to the supplier - unless somebody comes up with a way of producing the math image themselves. I think it can be done with MathJax, but I haven't looked into it.

Testing and developement

• There should be testing with reading systems and the assistive technologies that we have access to.
• The agencies should have tools to make math images themselves as well.

[Lisahartun]

But it is in MathML fundamentals? I would like to include it.

[samimaattaCelia]

Yes, it is in MathML 3 and MathML 4. If we strictly follow MathML Core, we shouldn't include the altimg. I do also think that we should include it, because some reading systems seem to support it (I haven't tested in a while, and don't remember though) and it will still be in MathML 4.

I also noticed that in the first comment I seem to have confused altimg and alttext and have talked about both of them. I will edit the comment.

[samimaattaCelia]

When writing the commit, I started thinking that is altimg only a visual fallback? Can you provide an alt text to it? How does it work together with alttext?