- * If $value consist of a list of two floats, it will be interpreted as
- * (actual value, maximum allowed value). The presence of a "-" in $key will cause
- * the first part of the key to be interpreted as a namespace.
+ * The key is used as the prefix for various messages used for formatting:
+ * - $key: The label for the field in the limit report
+ * - $key-value-text: Message used to format the value in the "NewPP limit
+ * report" HTML comment. If missing, uses $key-format.
+ * - $key-value-html: Message used to format the value in the preview
+ * limit report table. If missing, uses $key-format.
+ * - $key-value: Message used to format the value. If missing, uses "$1".
+ *
+ * Note that all values are interpreted as wikitext, and so should be
+ * encoded with htmlspecialchars() as necessary, but should avoid complex
+ * HTML for sanity of display in the "NewPP limit report" comment.