Important: #106192 - Add 'center' and 'font' to YAML processing removeTags 

See forge#106192

Description 

The HTML tags <font> and <center> have been officially deprecated for some time: see https://developer.mozilla.org/en-US/docs/Web/HTML/Element/font and https://developer.mozilla.org/en-US/docs/Web/HTML/Element/center.

The default YAML processing configuration file EXT:rte_ckeditor/Configuration/RTE/Processing.yaml has been changed to remove these HTML tags <font> and <center> by default when saving RTE field contents to the database.

This new default is adjusted with the option processing.HTMLparser_db.removeTags, which now also lists these two tags.

A stored input like <p><font face="Arial">My text</font></p> will - when saved - be changed to <p>My text</p>.

Affected installations 

All installations having <font> and <center> stored in their database fields, and where no custom RTE YAML configuration is in place that allows these tags.

Please note that due to issue forge#104839, this removeTags option was never properly applied previously, so the chances are that an installation never had output for font and center properly working anyway.

Also, note that CKEditor by default uses <span style="..."> tags to apply font formatting when using the Full preset.

Thus, the real-life impact should be low, but for legacy installations, you may want to convert existing data to replace font/html tags with their appropriate modern counterparts.

Migration 

Either accept the removal of these tags and use specific HTML tags like <span> and <div> to apply formatting.

Or adapt the RTE processing via TypoScript/YAML configuration to not have center and font in the processing.HTMLparser_db.removeTags list.

If the tags center and font have been configured via the editor.conf.style.definitions YAML option (not set by default), CKEditor would allow the use of these tags, but they will now be removed both when saving or when being rendered in the frontend. So these style definitions should be removed and/or adapted to <span style="..."> configurations.