Use the term "name" instead of "string" in the documentation, and add a
note explaining double quotes shouldn't be used for the quark name.
/**
* G_DEFINE_QUARK:
- * @QN: the string to return a #GQuark for
+ * @QN: the name to return a #GQuark for
* @q_n: prefix for the function name
*
* A convenience macro which defines a function returning the
- * #GQuark for the string @QN. The function will be named
+ * #GQuark for the name @QN. The function will be named
* @q_n<!-- -->_quark().
+ * Note that the quark name will be stringified automatically in the
+ * macro, so you shouldn't use double quotes.
*
* Since: 2.34
*/