If you find the article too long, just read the introduction and conclusion. The table of contents should help you skim.
{{< quotecaption partOfType="TechArticle" >}} HTML Living Standard, section 4.2.5.3: Pragma directives, Content Security Policy state {{< /quotecaption >}} {{At the time of inserting the
meta
element to the document, it is possible that some resources have already been fetched. For example, images might be stored in the list of available images prior to dynamically inserting ameta
element with anhttp-equiv
attribute in the Content security policy state. Resources that have already been fetched are not guaranteed to be blocked by a Content Security Policy that’s enforced late.