- * @param {Array} parser options
- * @return {Function} function suitable for assigning to jQuery plugin, such as $.fn.msg
+ * N.B. replacements are variadic arguments or an array in second parameter. In other words:
+ * somefunction( a, b, c, d )
+ * is equivalent to
+ * somefunction( a, [b, c, d] )
+ *
+ * We append to 'this', which in a jQuery plugin context will be the selected elements.
+ *
+ * @param {Object} options Parser options
+ * @return {Function} Function suitable for assigning to jQuery plugin, such as jQuery#msg
+ * @return {string} return.key Message key.
+ * @return {Array|Mixed} return.replacements Optional variable replacements (variadically or an array).
+ * @return {jQuery} return.return