I have recently upgraded a TinyMce editor in an Epi site from v 1.0.0 to 2.8.0. The old TinyMce editor had a button for the editors with the functionality to add a blockquote-element with the ability to add a cite- and/or title-attribute to the blockquote element.
This was an Episerver plugin to TinyMce with the name EPiQuote, is this plugin no longer available? Can't find any useful information.
I dug through the packages a bit and definitely appears it was removed in EPiServer.CMS.TinyMce 2.0.0, but I also couldn't find that referenced anywhere.
Seems to be a few blockquote plugins for TinyMCE (e.g. https://github.com/brouillon/blockquote) which should be relatively straightforward to add in 2.8.0 (https://world.episerver.com/documentation/developer-guides/CMS/add-ons/customizing-the-tinymce-editor-v2/plug-ins/#AddingPlugin).