Broken links

Hi!
I discovered a few broken links on the How to Meet WCAG
<https://www.w3.org/WAI/WCAG21/quickref/>.
For example:

   - FLASH11: Providing a longer text description of an object
   <https://www.w3.org/WAI/WCAG21/Techniques/flash/FLASH11.html>
   - There are a few more I believe..


That is located at 1.1.1
Non-text Content
Level A, under Long text alternative techniques for Situation B.

Allt gott,
Frida Lövborg @ Boid