It appears Pseudo elements pass AXE but fail F87 in WCAG

We had a discussion on WCAG call today regarding removal of the F87 Technique to fail content added with CSS psuedo Elements.

https://www.w3.org/TR/WCAG20-TECHS/F87.html

Some on the group proposed removing the failure including me, because most AT Browser combinations read this content. However, others said that:

- content added with CSS Pseudo elements will cause user style sheets that had pseudo elements to override the content
- that it makes it impossible to find the content CTRL+F in a browser
- doesn't work in IE 11 which is still prevelant.

So there was not consensus to remove F87 and technically a failure of WCAG to use this content. The WCAG group is not intending to remove the failure. Seems easy to identify this failure automatically in AXE. I propose adding a check.

To test current status:
http://davidmacd.com/blog/inserting-content-with-css-accessibility.html
Run axe on the page, no failure of the use of Pseudo elements.