Tag wiki excerpts are for quick plain text descriptions for:
- when the tag should be added to a question
- what other tag might be better, or
- a cursory note on what it represents.
When it starts to become a launch pad for other sites or pages to check out, it's time to dial it back.
Adding in the ability to format, link or imageificate the excerpt veers it into a canyon of oil slicked souls and renders it more promotional than information purposed for the community.
The rest of the tag wiki is open slather for links and other resources. A better place to grasp the sides of and pull it apart to allow better putting one's head up the tag's world of understanding and learning.
info
link in the excerpt dropdown (or thelearn more
link in the faq page header) if they want more detail.