The ArcGIS Hub and ArcGIS Enterprise Sites team is making important updates to the Site runtime with regard to your text card, header, and custom footer HTML. These updates have begun in ArcGIS Online and will reach ArcGIS Enterprise Sites at version 10.8.1.
For existing sites
As you edit your Site today in ArcGIS Online and ArcGIS Enterprise 10.8.1 (not yet released at this writing), you may start to notice raw HTML-like code appear. You will only see these start to appear while you are editing your site or if you click “View” from the Site editor. If, while doing these things, you see any raw HTML-like code then this means that the HTML you see is not supported (i.e. <script>) or is invalid HTML (i.e. <h7>). We recommend using an internet search engine for “HTML5″ + the tag you were trying to use to find valid alternatives.
For new sites
New Sites made today in ArcGIS Hub/ArcGIS Online follow the revised rules. New sites created using ArcGIS Enterprise Sites 10.8.1 will also follow the revised rules.
Visit our documentation for a full list of supported elements.
We strongly encourage you preview your Site in Hub before September 1, 2020. As of September 1st, the new rule set will be applied to all Sites—even those that had not yet been edited. Similarly, please make it a plan to edit all Sites in 10.8.1 on its release. Future releases of ArcGIS Enterprise will enforce the new ruleset.
Drop us a line on GeoNet if you have concerns or feel there is a tag that is being removed (sanitized) that shouldn’t be.