Improves popover text for rich text captions related settings

newscoop/src/Newscoop/NewscoopBundle/Resources/translations/system_pref.en.yml

@@ -147,8 +147,8 @@ newscoop:
       separator: "Specify the separator for Keywords in the Edit Article page (comma or hyphen)."
       stats: "This option enables the collection of statistics on reader access to publications on the server. You may wish to click No if you use a third-party statistical service, as disabling the collection of statistics may reduce the load on your Newscoop server."
       zoom: "If is set to Yes, readers can enlarge article images in your publications pages by clicking on them. This zooming feature works for any images inserted inline with the article text."
-      richtext_status: "Enable rich text editing for image captions."
-      richtext_length: "By default set to 255 (also when rich text captions are disabled). Use 0 for no limit."
+      richtext_status: "Enables a HTML editor for captions. Disabling rich text will escape, but not remove, any HTML present in the caption source. If disabled, the character limit will be fixed to 255, and any longer captions will be truncated the next time they are edited."
+      richtext_length: "The limit includes any HTML and defaults to 255 characters. Set 0 here to have unlimited caption lengths, if your theme supports them."
       ratio: "The resizing ratio takes precedence over any Resizing Width or Resizing Height value which is set here. If Ratio is not set but both Width and Height are set, then Newscoop will use the value which results in a smaller image size. The default settings here can be overridden by the ratio, width or height settings for a specific inline image set on the Article Edit page."
       replication: "Enables you to set up Newscoop to operate on two servers at once, which is a safety feature in case of hardware or network problems."
       filter: "Enter keywords for templates that you wish to hide from the template editor accessible via the Theme Management page. For example, templates that are no longer in use, but you do not wish to delete from the server."